Propylene polymer and block copolymer

ABSTRACT

Disclosed are a propylene polymer having a high crystallinity of a boiled heptane-insoluble component contained therein, a high stereoregularity and an extremely long mesochain (continuous propylene units wherein directions of α-methyl carbons are the same as each other), and a process for preparing said polymer. Also disclosed are a propylene block copolymer containing a crystalline polypropylene portion having a high crystallinity of a boiled heptane-insoluble component contained therein, a high stereoregularity and an extremely long mesochain, and a process for preparing said copolymer. Further disclosed is a propylene polymer composition comprising the above propylene polymer or propylene block copolymer and at least one stabilizer selected from a phenol type stabilizer, an organophosphite type stabilizer, a thioether type stabilizer, a hindered amine type stabilizer and a metallic salt of higher aliphatic acid. The propylene polymer of the invention is excellent in rigidity, heat resistance and moisture resistance, and can be favorably used for sheet, film, filament, injection molded product, blow molded product, etc. The propylene block polymer of the invention is well-balanced between rigidity, heat resistance and moisture resistance, and can be favorably used for sheet, filament, injection molded product, blow molded product, etc.

This application is a division of applicants copending applicationSerial No. 08/351,548, filed Dec. 7, 1994, now U.S. Pat. No. 6,274,678,which is a continuation of application Ser. No. 08/164,757, filed Dec.10, 1993, now abandoned, which is a division of application Ser. No.08/094,977, filed Jul. 22, 1993, now abandoned to all of whichapplicants claim priority.

FIELD OF THE INVENTION

The Present invention relates to a propylene polymer, a propylene blockcopolymer and process for the preparation thereof, and a propylenepolymer composition comprising the propylene polymer or the propyleneblock copolymer and a stabilizer. More particularly, the inventionrelates to a propylene polymer having a high crystallinity, a highstereoregularity and an extremely long mesochain (continuous propyleneunits wherein directions of ce-methyl carbons are the same as eachother), a propylene block copolymer containing a crystalline propyleneportion having a high crystallinity, a high stereoregularity and anextremely long mesochain, and a propylene polymer composition comprisingthe above propylene polymer or propylene block copolymer and an specificstabilizer.

BACKGROUND OF THE INVENTION

It has been well known that polyolefins such as crystallinepolypropylene are obtained by polymerizing olefins in the presence ofso-called Ziegler-Natta catalyst which comprises a compound of atransition metal of Group IV to Group VI in the periodic table and anorganometallic compound of a metal of Group I to Group III of theperiodic table. Recently, there have been made studies on a process inwhich crystalline polyolefins of high stereoregularity can be obtainedwith high polymerization activity using such catalysts as mentionedabove.

For example, Japanese Patent Laid-Open Publications No. 209207/1986, No.104810/1987, No. 104811/1987, No. 104812/1987, No. 104813/1987, No.311106/1989, No. 318011/1989 and No. 166104/1990 disclose thatpolyolefins of high stereoregularity can be obtained with highpolymerization activity by polymerizing olefins in the presence of acatalyst formed from a titanium-containing sold catalyst component whichcontains titanium, magnesium, halogen and an electron donor, anorganoaluminum compound and an electron donor.

The present applicant has also made a number of proposals with respectto a catalyst for olefin polymerization and an olefin polymerizationprocess by which crystalline polyolefin of high stereoregularity can beobtained with high polymerization activity, as described in, forexample, Japanese Patent Laid-Open Publications No. 108385/1975, No.126590/1975, No. 20297/1976, No. 28189/1976, No. 64586/1976, No.92885/1976, No. 133625/1976, No. 87489/1977, No. 100596/1977, No.147688/1977, No. 104593/1977, No. 2580/1978, No. 40093/1978, No.40094/1978, No. 43094/1978, No. 135102/1980, No. 135103/1980, No.152710/1980, No. 811/1981, No. 11908/1981, No. 18606/1981, No.83006/1983, No. 138705/1983, No. 138706/1983, No. 138707/1983, No.138708/1983, No. 138709/1983, No. 138710/1983, No. 138715/1983, No.138720/1983, No. 138721/1983, No. 215408/1983, No. 47210/1984, No.117508/1984, No. 117509/1984, No. 207904/1984, No. 206410/1984, No.206408/1984, No. 206407/1984, No. 69815/1986, No. 69821/1986, No.69822/1986, No. 69823/1986, No. 22806/1988, No. 95208/1988, No.199702/1988, No. 199703/1988, No. 202603/1988, No. 202604/1988, No.223008/1988, No. 223009/1988, No. 264609/1988, No. 87610/1989, No.156305/1989, No. 77407/1990, No. 84404/1990, No. 229807/1990, No.229806/1990 and No. 229805/1990.

Crystalline polypropylene is rigid and usually has a high heatdistortion temperature, a high melting point and a high crystallizationtemperature, and hence it shows excellent properties such as high heatresistance, high crystallization speed and high transparency.Accordingly, crystalline polypropylene has been applied to various usessuch as containers and films. Since rigidity and heat resistance ofpolypropylene are enhanced with increase of crystallinity, polypropylenehaving high crystallinity can be applied to such uses as require higherrigidity and higher heat resistance. Further, in the conventional uses,a product formed from the polypropylene can be made thin or an amount ofa filler to be added can be reduced, that is, weight-saving can beattained.

A propylene block copolymer usually comprises a crystallinepolypropylene portion and a non-crystalline polymer portion, and hasexcellent properties such as lightweight and good balance betweenrigidity, a heat distortion temperature and impact resistance.Accordingly, the propylene block copolymer has been applied to varioususes such as structural materials for containers and electricalappliances and automotive interior trims. Since rigidity and heatresistance of a propylene block copolymer are enhanced with increase ofcrystallinity of the crystalline polypropylene portion, a propyleneblock copolymer containing a polypropylene portion of high crystallinitycan be applied to such uses as require higher rigidity and higher heatresistance. Further, in the conventional uses, a product formed from thethe propylene block copolymer can be made thin or an amount of a fillerto be added can be reduced, that is, weight-saving can be attained.

The crystallinity of crystalline polypropylene has been conventionallyheightened by a method of adding a nucleating agent or other method, butthe conventional crystalline polypropylene has an isotactic pentad value(pentad isotacticity) by the NMR measurement of about 90 to 95%, and theimprovement of the rigidity and the heat resistance is limited to acertain extent. Accordingly, there have been keenly desired the adventof a crystalline polypropylene having a prominently high isotacticpentad value, namely a crystalline polypropylene having a highstereoregularity, and the advent of a propylene block copolymercontaining a crystalline polypropylene portion having a prominently highisotactic pentad value, namely a propylene block copolymer containing acrystalline polypropylene portion having a high stereoregularity.

Films made of the conventional crystalline polypropylene are not alwayssufficient in moisture resistance, and hence the advent of a crystallinepolypropylene excellent in the moisture resistance as well as in therigidity and the heat resistance has been also desired.

In the case of molding the above-mentioned crystalline polypropylene,moldability of a resin is improved when a melt viscosity of the resin islow, and hence a resin temperature is generally elevated to lower themelt viscosity of the resin. However, if the resin is molded at a hightemperature, the resin tends to be thermally decomposed or deterioratedto sometimes cause various problems such as coloring of the resultingmolded product, occurrence of cracks, lowering of long-term heatstability and weathering resistance, and reduction of rigidity and heatresistance.

Further, sheets or films made of the conventional crystallinepolypropylene are not always sufficient in the moisture resistance insome uses, and accordingly the advent of a crystalline polypropyleneexcellent in the moisture resistance as well as in the rigidity and theheat resistance has been desired.

The present inventors have earnestly studied to solve theabove-mentioned problems, and as a result, they have found that apropylene polymer composition comprising a propylene polymer (or apropylene block copolymer) which has a much higher stereoregularity thana conventional one and an extremely long mesochain and a specificstabilizer shows high rigidity, high heat resistance and high moistureresistance, and moreover is excellent in heat stability during themolding stage, long-term heat stability of the molded product andweathering resistance thereof as compared with a conventionalcrystalline polypropylene. Thus, the present invention has beenaccomplished.

OBJECT OF THE INVENTION

It is an object of the present invention to provide a propylene polymerwhich is excellent in rigidity, heat resistance and moisture resistanceand a process for preparing said propylene polymer.

It is another object of the present invention to provide a propyleneblock copolymer which is well balanced between rigidity, heat resistanceand impact resistance and a process for preparing said propylene blockcopolymer.

It is a further object of the present invention to provide a propylenepolymer composition comprising the above-mentioned propylene polymer orpropylene block copolymer and a stabilizer, which has excellentproperties of the propylene polymer or the propylene block copolymer andis capable of forming a molded product excellent in heat stabilityduring the molding stage, long-term heat stability and weatheringresistance.

SUMMARY OF THE INVENTION

The propylene polymer of the present invention is a propylene polymerhaving such properties that:

a melt flow rate (MFR) of said polymer at 230° C. under a load of 2.16kg is in the range of 0.1 to 500 g/10 min,

a pentad isotacticity [M₅] obtained from the following formula (1) usingabsorption intensity [Pmmmm] and [Pw] in a ¹³C-NMR spectrum of a boiledheptane-insoluble component contained in said polymer is in the range of0.970 to 0.995,

a pentad tacticity [M₃] obtained from the following formula (2) usingabsorption intensity [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr],[Prrrr] and [Pw] in a ¹³C-NMR spectrum of a boiled heptane-insolublecomponent contained in said polymer is in the range of 0.0020 to 0.0050,and

a crystallinity of a boiled heptane-insoluble component contained insaid polymer is not less than 60%; $\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack}} & (1)\end{matrix}$

wherein

[Pmmmm] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units which are bonded to eachother with meso form, and

[Pw] is absorption intensity of all methyl groups in a propylene unit;$\begin{matrix}{\left\lbrack M_{3} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack}} & (2)\end{matrix}$

wherein

[Pmmrm] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘ ┘ ┘) ┐ ┐in which ┘ and ┐ are each a propylene unit,

[Pmrmr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘ ┘) ┐ ┐^(┘) in which ┘ and ┐ are each a propylene unit,

[Pmrrr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘ ┘) ┐ ^(┘)┐ in which ┘ and ┐ are each a propylene unit,

[Prmrr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ┐ ^(┘ ┘) ┐^(┘) in which ┘ and ┐ are each a propylene unit,

[Prmmr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ┐ ^(┘ ┘ ┘) ┐in which ┘ and ┐ are each a propylene unit,

[Prrrr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘) ┐ ^(┘) ┐^(┘) in which ┘ and ┐ are each a propylene unit, and

[Pw] is absorption intensity of all methyl groups in a propylene unit.

The propylene polymer of the invention desirably contains 10-10,000 ppmof polymer comprising constituent units derived from a compoundrepresented by the following formula (i) or (ii):

H₂C═CH—X  (i)

H₂C═CH—CH₂—X  (ii)

wherein X is a cycloalkyl group, an aryl group or

M is carbon or silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group.

The propylene block copolymer of the present invention is a propyleneblock copolymer having such properties that:

a melt flow rate (MFR) of said copolymer at 230° C. under a load of 2.16kg is in the range of 0.1 to 500 g/10 min,

a pentad isotacticity [M₅] obtained from the following formula (1A)using absorption intensity [Pmmmm], [Pw], [Sαγ], [Sαδ⁺] and[Tδ⁺δ^(+] in a) ¹³C-NMR spectrum of a boiled heptane-insoluble componentcontained in said copolymer is in the range of 0.970 to 0.995,

a pentad tacticity [M₃] obtained from the following formula (2A) usingabsorption intensity [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr],[Prrrr], [Pw], [Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] in a ¹³C-NMR spectrum of aboiled heptane-insoluble component contained in said copolymer is in therange of 0.0020 to 0.0050, and

a crystallinity of a boiled heptane-insoluble component contained insaid copolymer is not less than 60%; $\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & \text{(1A)}\end{matrix}$

wherein

[Pmmmm] and [Pw] have the same meanings as defined in the aforementionedformula (1),

[Sαγ] is absorption intensity of such secondary carbons that are presentin a main chain and out of two kinds of tertiary carbons positionednearest to said secondary carbons one is situated at the α position andthe other is situated at the γ position,

[Sαδ⁺] is absorption intensity of such secondary carbons that arepresent in a main chain and out of two kinds of tertiary carbonspositioned nearest to said secondary carbons one is situated at the αposition and the other is situated at the δ position or farther than theδ position, and

[Tδ⁺δ⁺] is absorption intensity of such tertiary carbons that arepresent in a main chain and out of two kinds of tertiary carbonspositioned nearest to said tertiary carbons one is situated at the δposition or farther than the δ position and the other is also situatedat the δ position or farther than the δ position; $\begin{matrix}{\left\lbrack M_{3} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & \text{(2A)}\end{matrix}$

wherein

[Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr], [Prrrr] and [Pw] have thesame meanings as defined in the aforementioned formula (2), and

[Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] have the same meanings as defined in theabove-mentioned formula (1A).

The propylene block copolymer of the invention desirably contains10-10,000 ppm of polymer comprising constituent units derived from acompound represented by the aforementioned formula (i) or (ii).

The first process for preparing a propylene polymer according to thepresent invention is a process for preparing a propylene polymer havinga crystallinity of not less than 60%, which comprises polymerizingpropylene in the presence of a catalyst for olefin polymerizationcomprising:

[I] a prepolymerized catalyst obtained by prepolymerizing at least onereactive monomer represented by the following formula (i) or (ii) using(a) a solid titanium catalyst component containing magnesium, titanium,halogen and an electron donor as essential components and (b) anorganometallic catalyst component, said reactive monomer beingprepolymerized in an amount of 0.1 to 1,000 g per 1 g of the solidtitanium catalyst component (a);

H₂C═CH—X   (i)

H₂C═CH—CH₂—X   (ii)

wherein X is a cycloalkyl group, an aryl group or

M is carbon or silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group;

[II] the organometallic catalyst component (b); and

[III] a silicon compound represented by the following formula (iii) or acompound having at least two ether linkages existing via plurality ofatoms:

R^(a) _(n)—Si—(OR^(b))_(4−n)  (iii)

wherein, n is 1, 2 or 3; when n is 1, R^(a) is a secondary or a tertiaryhydrocarbon group; when n is 2 or 3, at least one of Ra is a secondaryor a tertiary hydrocarbon group, R^(a) may be the same or different, andR^(b) is a hydrocarbon group of 1 to 4 carbon atoms; and when 4−n is 2or 3, R^(b) may be the same or different;

in said process, propylene being polymerized in an amount of 3,000 to1,000,000 g per 1 g of the solid titanium catalyst component (a)contained in the prepolymerized catalyst.

The second process for preparing a propylene polymer according to thepresent invention is a process which comprises preparing a propylenepolymer having an intrinsic viscosity [η] of 3 to 40 dl/g in an amountof 0.1 to 55% by weight based on the amount of the resulting polymerusing one or more polymerizers out of two or more polymerizers and thenfurther preparing a propylene polymer using the residual polymerizers,in the presence of a catalyst for olefin polymerization comprising:

[I] a prepolymerized catalyst obtained by prepolymerizing at least onereactive monomer represented by the following formula (i) or (ii) using(a) a solid titanium catalyst component containing magnesium, titanium,halogen and an electron donor as essential components and (b) anorganometallic catalyst component, said reactive monomer beingprepolymerized in an amount of 0.1 to 1,000 g per 1 g of the solidtitanium catalyst component (a);

H₂C═CH—X   (i)

H₂C═CH—CH₂—X   (ii)

wherein X is a cycloalkyl group, an aryl group or

M is carbon or silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group;

[II] the organometallic catalyst component (b); and

[III] a silicon compound represented by the following formula (iii) or acompound having at least two ether linkages existing via plurality ofatoms:

R^(a) _(n)—Si—(OR^(b))_(4−n)   (iii)

wherein, n is 1, 2 or 3; when n is 1, R^(a) is a secondary or a tertiaryhydrocarbon group; when n is 2 or 3, at least one of Ra is a secondaryor a tertiary hydrocarbon group, R^(a) may be the same or different, andR^(b) is a hydrocarbon group of 1 to 4 carbon atoms; and when 4−n is 2or 3, R^(b) may be the same or different;

the propylene polymer obtained by said process satisfying the followingrequisites:

(a) a crystallinity of said polymer is not less than 60%,

(b) a melt flow rate of said polymer at 230° C. is in the range of 0.1to 500 g/10 min, and

(c) said polymer is a propylene polymer obtained by polymerizingpropylene in an amount of 3,000 to 100,000 g per 1 g of the solidtitanium catalyst component (a).

The process for preparing a propylene block copolymer according to thepresent invention is a process which comprises a first polymerizationstage for homopolymerizing propylene or copolymerizing propylene withethylene and/or α-olefin of 4 to 10 carbon atoms to prepare acrystalline polymer and a second polymerization stage for copolymerizingtwo or more monomers selected from α-olefin of 2 to 20 carbon atoms toprepare a low-crystalline or non-crystalline copolymer, in the presenceof a catalyst for olefin polymerization comprising:

[I] a prepolymerized catalyst obtained by prepolymerizing at least onereactive monomer represented by the following formula (i) or (ii) using(a) a solid titanium catalyst component containing magnesium, titanium,halogen and an electron donor as essential components and (b) anorganometallic catalyst component, said reactive monomer beingprepolymerized in an amount of 0.1 to 1,000 g per 1 g of the solidtitanium catalyst component (a);

H₂C═CH—X   (i)

H₂C═CH—CH₂—X   (ii)

wherein X is a cycloalkyl group, an aryl group or

M is carbon or silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group;

[II] the organometallic catalyst component (b); and

[III] a silicon compound represented by the following formula (iii) or acompound having at least two ether linkages existing via plurality ofatoms:

R^(a) _(n)—Si—(OR^(b))_(4−n)   (iii)

wherein, n is 1, 2 or 3; when n is 1, R^(a) is a secondary or a tertiaryhydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or a tertiary hydrocarbon group, Ra may be the same ordifferent, and R^(b) is a hydrocarbon group of 1 to 4 carbon atoms; andwhen 4−n is 2 or 3, R^(b) may be the same or different.

The first propylene polymer composition of the present inventioncomprises:

[A1] a propylene polymer having such properties that

a melt flow rate (MFR) of said polymer at 230° C. under a load of 2.16kg is in the range of 0.1 to 500 g/10 min,

a pentad isotacticity [M₅] obtained from the aforesaid formula (1) usingabsorption intensity [Pmmmm] and [Pw] in a ¹³C-NMR spectrum of a boiledheptane-insoluble component contained in said polymer is in the range of0.970 to 0.995,

a pentad tacticity [M₃] obtained from the aforesaid formula (2) usingabsorption intensity [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr],[Prrrr] and [Pw] in a ¹³C-NMR spectrum of a boiled heptane-insolublecomponent contained in said polymer is in the range of 0.0020 to 0.0050,and

a crystallinity of a boiled heptane-insoluble component contained insaid polymer is not less than 60%; and

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts by weightbased on 100 parts by weight of the propylene polymer.

The second propylene polymer composition of the present inventioncomprises:

[A1] the above mentioned propylene polymer,

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts by weightbased on 100 parts by weight of the propylene polymer; and

at least one compound selected from the group consisting of [C] anorganophosphite type stabilizer, [D] a thioether type stabilizer, [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight based on 100parts by weight of the propylene polymer.

The third propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer, and

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene polymer.

The fourth propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer,

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene polymer, and

at least one compound selected from the group consisting of [DJ athioether type stabilizer, [E] a hindered amine type stabilizer and [F]a metallic salt of a higher aliphatic acid in an amount of 0.001 to 10parts by weight based on 100 parts by weight of the propylene polymer.

The fifth propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer, and

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight based on 100 parts by weight of the propylene polymer.

The sixth propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer,

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight based on 100 parts by weight of the propylene polymer, and

at least one compound selected from the group consisting of [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight based on 100parts by weight of the propylene polymer.

The seventh propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer, and

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene polymer.

The eighth propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer,

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene polymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight based on 100 parts by weight of the propylenepolymer.

The ninth propylene polymer composition of the present inventioncomprises:

[A1] the above-mentioned propylene polymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight based on 100 parts by weight of the propylenepolymer.

The propylene polymer used in each of the first to ninth propylenepolymer compositions of the invention preferably contains 10-10,000 ppmof polymer comprising constituent units derived from a compoundrepresented by the aforesaid formula (i) or (ii).

Such propylene polymer compositions as described above have propertiesof the propylene polymer and is excellent in heat stability during themolding stage, long-term heat stability and weathering resistance.

The tenth propylene polymer composition of the present inventioncomprises:

[A2] a propylene block copolymer having such properties that

a melt flow rate (MFR) of said copolymer at 230° C. under a load of 2.16kg is in the range of 0.1 to 500 g/10 min,

a pentad isotacticity [M₅] obtained from the aforesaid formula (1A)using absorption intensity [Pmmmm], [Pw], [Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] in a¹³C-NMR spectrum of a boiled heptane-insoluble component contained insaid copolymer is in the range of 0.970 to 0.995,

a pentad tacticity [M₃] obtained from the aforesaid formula (2A) usingabsorption intensity [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr],[Prrrr], [Pw], [Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] in a ¹³C-NMR spectrum of aboiled heptane-insoluble component contained in said copolymer is in therange of 0.0020 to 0.0050, and

a crystallinity of a boiled heptane-insoluble component contained insaid copolymer is not less than 60%; and

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts by weightbased on 100 parts by weight of the propylene block copolymer.

The eleventh propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer,

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts by weightbased on 100 parts by weight of the propylene block copolymer; and

at least one compound selected from the group consisting of [C] anorganophosphite type stabilizer, [D] a thioether type stabilizer, [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight based on 100parts by weight of the propylene block copolymer.

The twelfth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer, and

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene block copolymer.

The thirteenth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer,

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene block copolymer,and

at least one compound selected from the group consisting of [D] athioether type stabilizer, [E] a hindered amine type stabilizer and [F]a metallic salt of a higher aliphatic acid in an amount of 0.001 to 10parts by weight based on 100 parts by weight of the propylene blockcopolymer.

The fourteenth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer, and

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight based on 100 parts by weight of the propylene block copolymer.

The fifteenth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer,

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight based on 100 parts by weight of the propylene block copolymer,and

at least one compound selected from the group consisting of [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight based on 100parts by weight of the propylene block copolymer.

The sixteenth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer, and

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene block copolymer.

The seventeenth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer,

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight based on 100 parts by weight of the propylene block copolymer,and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight based on 100 parts by weight of the propylene blockcopolymer.

The eighteenth propylene polymer composition of the present inventioncomprises:

[A2] the above-mentioned propylene block copolymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight based on 100 parts by weight of the propylene blockcopolymer.

The propylene block copolymer used in each of the tenth to eighteenthpropylene polymer compositions of the invention preferably contains10-10,000 ppm of polymer comprising constituent units derived from acompound represented by the aforesaid formula (i) or (ii).

Such propylene polymer compositions as described above have propertiesof the propylene polymer and is excellent in heat stability during themolding stage, long-term heat stability and weathering resistance.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrate steps of a process for preparing a catalyst for olefinpolymerization which is used for the preparation of a propylene polymeror a propylene block copolymer according to the present invention.

FIG. 2 also illustrate steps of a process for preparing a catalyst forolefin polymerization which is used for the preparation of a propylenepolymer or a propylene block copolymer according to the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The propylene polymer, the propylene block copolymer, the process forpreparing said polymer or said copolymer and the propylene polymercomposition according to the present invention are described in detailhereinafter.

The term “polymerization” used in this specification means not onlyhomopolymerization but also copolymerization, and the term “polymer”used in this specification means not only homopolymer but alsocopolymer.

The propylene polymer according to the invention is a homopolymer ofpropylene.

The propylene polymer has a melt flow rate (MFR), as measured at 230° C.under a load of 2.16 kg, of 0.1 to 500 g/10 min, preferably 0.2 to 300g/10 min. Measurement of the melt flow rate (MFR) is carried out inaccordance with ASTM D1238-65T under the conditions of a temperature of230° C. and a load of 2.16 kg.

In the propylene polymer of the invention, a pentad isotacticity [M₅]obtained from the following formula (1) using absorption intensity[Pmmmm] and [Pw] in a ¹³C-NMR spectrum of a boiled heptane-insolublecomponent contained in said polymer is in the range of 0.970 to 0.995,preferably 0.980 to 0.995, more preferably 0.982 to 0.995.$\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack}} & (1)\end{matrix}$

wherein

[Pmmmm] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units which are bonded to eachother with meso form, and

[Pw] is absorption intensity of all methyl groups in a propylene unit.

The propylene block copolymer according to the invention is a blockcopolymer comprises:

a crystalline polypropylene portion which comprises constituent unitsderived from ethylene and/or olefin of 4 to 10 carbon atoms in an amountof 0 to 20% by mol and constituent units derived from propylene, and

a low-crystalline or non-crystalline copolymer portion which containstwo or more kinds of constituent units derived from olefin of 2 to 20carbon atoms.

In this propylene block copolymer, it is desired that the constituentunites derived from propylene are contained in an amount of 50 to 98% bymol, preferably 60 to 97% by mol, and the constituent units derived fromethylene and/or olefin of 4 to 10 carbon atoms are contained in anamount of 50 to 2% by mol, preferably 40 to 3% by mol.

Concrete examples of the olefins of 4 to 20 carbon atoms include1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene,1-octene, 3-methyl-1-butene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, cyclopentene, cycloheptene,norbornene, 5-ethyl-2-norbornene, tetracyclododecene and2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene. Theconstituent units derived from the above-exemplified olefins of 4 to 20carbon atoms or derived from ethylene may be contained in combination oftwo or more kinds.

The propylene block copolymer has a melt flow rate (MFR), as measured at230° C. under a load of 2.16 kg, of 0.1 to 500 g/10 min, preferably 0.2to 300 g/10 min. Measurement of the melt flow rate (MFR) is carried outin accordance with ASTM D1238-65T under the conditions of a temperatureof 230° C. and a load of 2.16 kg.

In the propylene block copolymer of the invention, a pentad isotacticity[M₅] obtained from the following formula (1A) using absorption intensity[Pmmmm], [Pw], [Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] in a ¹³C-NMR spectrum of aboiled heptane-insoluble component is in the range of 0.970 to 0.995,preferably 0.980 to 0.995, more preferably 0.982 to 0.995.$\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & \text{(1A)}\end{matrix}$

wherein

[Pmmmm] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units which are bonded to eachother with meso form,

[Pw] is absorption intensity of all methyl groups in a propylene unit,

[Sαγ] is absorption intensity of such secondary carbons that are presentin a main chain and out of two kinds of tertiary carbons positionednearest to said secondary carbons one is situated at the α position andthe other is situated at the γ position,

[Sαδ⁺] is absorption intensity of such secondary carbons that arepresent in a main chain and out of two kinds of tertiary carbonspositioned nearest to said secondary carbons one is situated at the αposition and the other is situated at the δ position or farther than theδ position, and

[Tδ⁺δ⁺] is absorption intensity of such tertiary carbons that arepresent in a main chain and out of two kinds of tertiary carbonspositioned nearest to said tertiary carbons one is situated at the δposition or farther than the δ position and the other is also situatedat the δ position or farther than the δ position.

Next, the pentad isotacticity [M₅] used for evaluating thestereoregularity of the boiled heptane-insoluble component contained inthe propylene polymer and the propylene block copolymer of the inventionis concretely described below.

When the boiled heptane-insoluble component is a homopolymer ofpropylene, this insoluble component can be expressed by the followingformula (A):

If a propylene unit

is symbolized by ┘ or ┐, ┘ ┘ is expressed by “m” (meso form), and ┘ ┐ isexpressed by “r” (racemo form), continuous five propylene isotacticunits are expressed by ^(┘)m^(┘)m^(┘)m^(┘)m ^(┘). When absorptionintensity, in a ¹³C-NMR spectrum, of methyl groups (e.g., Me³, Me⁴) inthe third unit among the continuous five propylene units which arebonded to each other with meso form is expressed by [Pmmmm], andabsorption intensity of the whole methyl groups (e.g., Me¹, Me², Me³ . .. ) in the propylene units is expressed by [Pw], the stereoregularity ofthe boiled heptane-insoluble component represented by the above formula(A) can be evaluated by a ratio of [Pmmmm] to [Pw], namely a value of[M₅] obtained from the following formula (1).

Accordingly, the stereoregularity of the boiled heptane-insolublecomponent in the propylene polymer of the invention can be evaluated bya value of the pentad isotacticity [M₅] obtained from the followingformula (1) using the absorption intensity [Pmmmm] and [Pw] in a ¹³C-NMRspectrum of the boiled heptane-insoluble component. $\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack}} & (1)\end{matrix}$

Further, when the boiled heptane-insoluble component containsconstituent units derived from other olefins than propylene, forexample, ethylene units, in a small amount, said insoluble component canbe expressed by the following formula (B-1) or (B-2). The formula (B-1)shows that one ethylene unit is contained in a propylene unit chain, andthe formula (B-2) shows that an ethylene unit chain composed of two ormore ethylene units is contained in a propylene unit chain.

In the above cases, for measurement of the pentad isotacticity, theabsorption intensity of other methyl groups (Me⁴, Me⁵, Me⁶ and Me⁷ inthe formulas (B-1) and (B-2)) than the methyl group in the third unitamong the continuous five isotactic propylene units should betheoretically excluded. However, absorption of these methyl groups areobserved to be overlapped on absorption of other methyl groups, andhence it is difficult to quantitatively determine the absorptionintensity of those methyl groups.

On that account, when the boiled heptane-insoluble component isrepresented by the formula (B-1), absorption intensity (Sαγ), in the¹³C-NMR spectrum, of a secondary carbon (C¹) which is in the ethyleneunit and bonded to a tertiary carbon (C^(a)) in the propylene unit andabsorption intensity (Sαγ) of a secondary carbon (C³) which is in thepropylene unit and bonded to the secondary carbon (C²) in the ethyleneunit are excluded.

In other words, the absorption intensity of other methyl groups (Me⁴,Me⁵, Me⁶ and Me⁷) than the methyl groups in the third unit among thecontinuous five isotactic propylene units are excluded by subtracting,from Pw, two times value of the absorption intensity (Sαγ) of such asecondary carbon (C¹ or C³) that said secondary carbon is present in amain chain and out of two tertiary carbons positioned nearest to saidsecondary carbon one (C^(a) or C^(b)) is situated at the α position andthe other (C^(b) or C^(a)) is situated at the γ position.

When the boiled heptane-insoluble component is represented by theformula (B-2), absorption intensity (Sαδ⁺), in the ¹³C-NMR spectrum, ofa secondary carbon (C⁴) which is in the ethylene unit chain composed oftwo or more ethylene units and bonded to a tertiary carbon (C^(d)) inthe propylene unit and absorption intensity (Sαδ⁺) of a secondary carbon(C⁶) which is in the propylene unit and bonded to a secondary carbon(C⁵) in the ethylene unit chain composed of two or more ethylene unitsare excluded.

In other words, the absorption intensity of other methyl groups (Me⁴,Me⁵, Me⁶ and Me⁷) than the methyl groups in the third unit among thecontinuous five isotactic propylene units are excluded by subtracting,from Pw, two times value of the absorption intensity [Sαδ⁺] of such asecondary carbon (C⁴ or C⁶) that said secondary carbon is present in amain chain and out of two tertiary carbons positioned nearest to saidsecondary carbon one (C^(d) or C^(e)) is situated at the α position andthe other (C^(e) or C^(d)) is situated at the δ position or farther thanthe δ position.

Accordingly, the stereoregularity of the boiled heptane-insolublecomponent represented by the above formula (B-1) or (B-2) can beevaluated by a value obtained from the following formula (1B).$\begin{matrix}\frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}}\quad \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)}} & \text{(1B)}\end{matrix}$

When the boiled heptane-insoluble component contains a small amount ofethylene units and the ethylene unit chain contains one propylene unit,this insoluble component can be represented by the following formula(C).

If the aforementioned formula (1B) is applied to the above case, afurther correction should be carried out.

The reason is that there are four methyl groups corresponding to Sαγ orSαδ⁺ in spite that the number of the methyl groups to be excluded isfive (Me⁴, Me⁵, Me⁶, Me⁷ and Me⁸), and hence if the formula (1B) isapplied, the number of the excluded methyl groups is larger by threethan the number of other methyl groups than the methyl group in thethird unit among the continuous five propylene units.

Accordingly, a further correction is made by using absorption intensity,in the ¹³C-NMR spectrum, of a tertiary carbon in the propylene unitcontained in the ethylene unit chain. In other words, the correction ismade by adding, to Pw, a value of three times of absorption intensity[Tδ⁺δ⁺] of such a tertiary carbon (C⁷) that said tertiary carbon ispresent in a main chain and out of two tertiary carbons (C^(f), C^(g))positioned nearest to said tertiary carbon one (C^(f)) is situated atthe δ position or farther than the δ position and the other (C^(g)) isalso situated at the δ position or farther than the δ position.

Thus, the stereoregularity of the boiled heptane-insoluble componentrepresented by the above formula (C) can be evaluated by a value of thepentad isotacticity [M₅] obtained from the following formula (1A).

Accordingly, the stereoregularity of the boiled heptane-insolublecomponent in the propylene block copolymer of the invention can beevaluated by a value of the pentad isotacticity [M₅] obtained from thefollowing formula (1A). $\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & \text{(1A)}\end{matrix}$

The formula (1) and the formula (1B) are not different from the formula(1A), and they can be said to be special cases of the formula (1A).Further, the above-mentioned correction may become unnecessary dependingon the kind of constitution unit other than propylene which is containedin the boiled heptane-insoluble components.

In the propylene polymer of the invention, the pentad isotacticity [M₅]of the boiled heptane-insoluble component obtained from the aboveformula (1) is in the range of 0.970 to 0.995, and a pentad tacticity[M₃] obtained from the following formula (2) using absorption intensity[Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr], [Prrrr] and [Pw] in a¹³C-NMR spectrum of the boiled heptane-insoluble component is in therange of 0.0020 to 0.0050, preferably 0.0023 to 0.0045, more preferably0.0025 to 0.0040. $\begin{matrix}{\left\lbrack M_{3} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack}} & (2)\end{matrix}$

wherein

[Pmmrm] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘ ┘ ┘) ┐ ┐in which ┘ and ┐ are each a propylene unit,

[Pmrmr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘ ┘) ┐ ┐^(┘) in which ┘ and ┐ are each a propylene unit,

[Pmrrr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘ ┘) ┐ ^(┘)┐ in which ┘ and ┐ are each a propylene unit,

[Prmrr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ┐ ^(┘ ┘) ┐^(┘) in which ┘ and ┐ are each a propylene unit,

[Prmmr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ┐ ^(┘ ┘ ┘) ┐in which ┘ and ┐ are each a propylene unit,

[Prrrr] is absorption intensity of methyl groups present in the thirdunit among continuous five propylene units represented by ^(┘) ┐ ^(┘) ┐^(┘) in which ┘ and ┐ are each a propylene unit, and

[Pw] has the same meaning as defined in the above formula (1).

In the propylene block copolymer of the invention, the pentadisotacticity [M₅] of the boiled heptane-insoluble component obtainedfrom the aforesaid formula (1A) is in the range of 0.970 to 0.995, and apentad tacticity [M₃] obtained from the following formula (2A) usingabsorption intensity [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr],[Prrrr], [Pw], [Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] in a ¹³C-NMR spectrum of theboiled heptane-insoluble component is in the range of 0.0020 to 0.0050,preferably 0.0023 to 0.0045, more preferably 0.0025 to 0.0040.$\begin{matrix}{\left\lbrack M_{3} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & \text{(2A)}\end{matrix}$

wherein [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr] and [Prrrr] have thesame meanings as defined in the formula (2), and [Pw], [Sαγ], [Sαδ⁺] and[Tδ^(+δ) ⁺] have the same meanings as defined in the formula (1A).

In the formula (2) and the formula (2A), each of [Pmmrm], [Pmrmr],[Pmrrr], [Prmrr], [Prmmr] and [Prrrr] shows absorption intensity of amethyl group in the third unit among continuous five propylene unitshaving such a structure that three out of five methyl groups in thecontinuous five propylene units are the same in the direction and theresidual two are different in the direction (sometimes referred to as“M₃ structure” hereinafter). That is, the value of the pentad tacticity[M₃] obtained from the above formula (2) exhibits a proportion of the M₃structure in the propylene unit chain, while the value of the pentadtacticity [M₃] obtained from the above formula (2A) exhibits aproportion of the M₃ structure in the propylene unit chain containing asmall amount of other monomer units than the propylene units.

The propylene polymer of the invention has an extremely long mesochain(i.e., propylene unit chain in which directions of α-methyl carbons arethe same as each other), because the value of the pentad isotacticity[M₅] of the boiled heptane-insoluble component obtained from the formula(1) is in the range of 0.970 to 0.995, and the value of the pentadtacticity [M₃] of the boiled heptane-insoluble component obtained fromthe formula (2) is in the range of 0.0020 to 0.0050.

The crystalline propylene portion of the propylene block copolymer ofthe invention has an extremely long mesochain, because the value of thepentad isotacticity [M₅] of the boiled heptane-insoluble componentobtained from the formula (1A) is in the range of 0.970 to 0.995, andthe value of the pentad tacticity [M₃] of the boiled heptane-insolublecomponent obtained from the formula (2A) is in the range of 0.0020 to0.0050.

In general, polypropylene has a longer mesochain as the value of thepentad tacticity [M₃] becomes smaller. However, when the value of thepentad isotacticity [M₅] is extremely large and the value of the pentadtacticity [M₃] is extremely small, polypropylene having a larger valueof the pentad tacticity [M₃] sometimes has a longer mesochain with theproviso that the pentad isotacticity [M₅] is almost the same.

For example, when polypropylene having the following structure (a) iscompared with polypropylene having the following structure (b), thepolypropylene represented by the structure (a) having the M₃ structurehas a longer mesochain than the polypropylene represented by thestructure (b) not having the M₃ structure. (Each of the followingstructures (a) and (b) is composed of 1,003 propylene units.)

The pentad isotacticity [M₅] of polypropylene represented by thestructure (a) is 0.986, and the pentad isotacticity [M₅] ofpolypropylene represented by the structure (b) is 0.985, so that thosevalues are almost the same. However, in the polypropylene represented bythe structure (a) having the M₃ structure, the number of propylene unitscontained in the mesochain is 497 on an average, while in thepolypropylene represented by the structure (b) not having the M₃structure, the number of propylene units contained in the mesochain is250 on an average. That is, in the polypropylene having an extremelylarge value of the pentad isotacticity [M₅], a proportion of thestructure represented by “r” (racemo) contained in the propylene unitchain becomes extremely small. Hence, the polypropylene whereinstructures represented by “r” (racemo) are concentrated (i.e.,polypropylene having the M₃ structure) has a longer mesochain ascompared with the polypropylene wherein structures represented by “r”(racemo) are scattered (i.e., polypropylene not having the M₃structure).

The propylene polymer of the invention is a highly crystallinepolypropylene having the M₃ structure represented by the above structure(a), and in this polymer, the pentad isotacticity [M₅] of the boiledheptane-insoluble component is in the range of 0.970 to 0.995, and thepentad tacticity [M₃] of the boiled heptane-insoluble component is inthe range of 0.0020 to 0.0050. Such propylene polymer of the inventionhas higher rigidity, heat resistance and moisture resistance than thoseof the conventional highly crystalline polypropylene, though the reasonhas not been clarified. If the pentad tacticity [M₃] of the boiledheptane-insoluble component is out of the range of 0.0020 to 0.0050, theabove-mentioned properties are sometimes deteriorated.

The propylene block copolymer of the invention contains a highlycrystalline polypropylene portion having the M₃ structure represented bythe above structure (a), and in this copolymer, the pentad isotacticity[M₅] of the boiled heptane-insoluble component is in the range of 0.970to 0.995, and the pentad tacticity [M₃] of the boiled heptane-insolublecomponent is in the range of 0.0020 to 0.0050. Such propylene blockcopolymer of the invention has a better balance between rigidity, heatresistance and impact resistance than the conventional highlycrystalline polypropylene, though the reason has not been clarified. Ifthe pentad tacticity [M₃] of the boiled heptane-insoluble component isout of the range of 0.0020 to 0.0050, the above-mentioned properties aresometimes deteriorated.

In the invention, the boiled heptane-insoluble component is prepared asfollows. In a 1-liter flask equipped with a stirring device is charged 3g of a polymer sample, 20 mg of 2,6-di-tert-butyl-4-methylphenol and 500ml of n-decane, and the flask is heated in an oil bath of 145° C. todissolve the polymer sample. After the polymer sample is dissolved, theflask is cooled to room temperature over about 8 hours and then kept for8 hours in an water bath of 23° C. The n-decane suspension containingthe precipitated polymer (23° C.-decane-insoluble component) is filteredon a glass filter of G-4 (or G-2) and dried under a reduced pressure.Then, 1.5 g of the polymer is subjected to Soxhlet extraction for notshorter than 6 hours using heptane. Thus, a boiled heptane-insolublecomponent as a test sample is obtained.

The amount of the boiled heptane-insoluble component in the propylenepolymer of the invention is usually not less than 80% by weight,preferably not less than 90% by weight, more preferably not less than94% by weight, much more preferably not less than 95% by weight,particularly preferably not less than 96% by weight.

The amount of the boiled heptane-insoluble component in the propyleneblock copolymer of the invention largely depends upon the amount of the23° C.-decane-soluble component and cannot be determinedunconditionally, but the boiled heptane-insoluble component in the 23°C.-decane-insoluble portion is usually not less than 80% by weight,preferably not less than 85% by weight, more preferably not less than90% by weight, much more preferably not less than 93% by weight,particularly preferably not less than 94% by weight.

The amount of the boiled heptane-insoluble component is determined onthe assumption that the 23° C.-decane-soluble component is also solublein the boiled heptane.

In the invention, the NMR measurement of the boiled heptane-insolublecomponent is carried out, for example, in the following manner. That is,0.35 g of the boiled heptane-insoluble component is dissolved in 2.0 mlof hexachlorobutadiene under heating. The resulting solution is filteredover a glass filter (G2), to the filtrate is added 0.5 ml of deuteratedbenzene, and the mixture is charged in a NMR tube having an innerdiameter of 10 mm. Then, ¹³C-NMR measurement is conducted at 120° C.using a NMR measuring apparatus (GX-500 type produced by Japan ElectronCo., Ltd). The number of integration times is not less than 10,000. Thevalues of the pentad isotacticity [M₅] and the pentad tacticity [M₃] canbe sought from peak intensity based on each structures obtained by theabove-mentioned measurement or the sum of the peak intensity.

The boiled heptane-insoluble component in the propylene polymer of theinvention has a crystallinity of usually not less than 60%, preferablynot less than 65%, more preferably not less than 70%.

The boiled heptane-insoluble component in the propylene block copolymerof the invention has a crystallinity of usually not less than 60%,preferably not less than 65%, more preferably not less than 68%.

The crystallinity can be determined as follows. A sample is molded intoan angular plate having a thickness of 1 mm by means of a pressuremolding machine of 180° C., and immediately the plate is water cooled toobtain a pressed sheet. Using this pressed sheet, the crystallinity ismeasured by a measuring device (Rotor Flex RU300 produced by RigakuDenki K.K., output: 50kV, 250 mA). In this measurement, a transmissionmethod is utilized, and the measurement is conducted while rotating thesample.

The propylene polymer or the propylene block copolymer of the inventiondesirably contains polymer comprising constituent units derived from acompound represented by the following formula (i) or (ii) in an amountof 10 to 10,000 ppm, preferably 100 to 5,000 ppm.

H₂C═CH—X   (i)

H₂C═CH—CH₂—X   (ii)

wherein X is a cycloalkyl group, an aryl group or

M is carbon or Silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group.

Examples of the cycloalkyl group indicated by X in the above formula (i)or (ii) include a cyclopentyl group, cyclohexyl group, a cycloheptylgroup, and examples of the aryl group indicated by X is a phenyl group,a tolyl group, a xylyl group and a naphthyl group.

Examples of the hydrocarbon group indicated by R¹, R² or R³ in the aboveformula (i) or (ii) include an alkyl group such as a methyl group, anethyl group, a propyl group and a butyl group; an aryl group such as aphenyl group and a naphthyl group; and a norbornyl group. Further, thehydrocarbon group indicated by R¹, R² or R³ may contain silicon andhalogen.

Concrete examples of the compound represented by the formula (i) or (ii)include 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene,4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene,4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene,allylnaphthalene, allylnorbornane, styrene, dimethylstyrenes,vinylnaphthalenes, allyltoluenes, allylbenzene, vinylcyclohexane,vinylcyclopentane, vinylcycloheptane and allyltrialkylsilanes. Of these,preferred are 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-hexene,vinylcyclohexane, allyltrimethylsilane and dimethylstyrene. Morepreferred are 3-methyl-1-butene, vinylcyclohexane andallyltrimethylsilane. Particularly preferred is 3-methyl-1-butene.

Further, the propylene polymer of the invention may contain constituentunits derived from olefins having 20 or less carbon atoms other thanpropylene in a small amount or may contain constituent units derivedfrom diene compounds having 4 to 20 carbon atoms in a small amount.

The propylene block copolymer of the invention may contain constituentunits derived from diene compounds having 4 to 20 carbon atoms such as1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, 1,3-hexadiene,1,4-hexadiene, 1,5-hexadiene, 4-methyl-1,4-hexadiene,5-methyl-1,4-hexadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene,6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene,6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1, 6-nonadiene,7-ethyl-1, 6-nonadiene, 6-methyl-1,6-decadiene, 7-methyl-1,6-decadiene,6-methyl-1,6-undecadiene, 1,7-octadiene, 1,9-decadiene, isoprene,butadiene, ethylidenenorbornene, vinylnorbornene and dicylopentadiene,in an amount of not more than 5% by mol.

The propylene polymer of the invention desirably has a density of 0.900to 0.936 g/cm³, preferably 0.910 to 0.936 g/cm³. The propylene blockcopolymer of the invention desirably has a density of 0.900 to 0.936g/cm³, preferably 0.910 to 0.936 g/cm³.

In the propylene polymer of the invention, it is desired that the amountof the 23° C.-decane-soluble component is not more than 3.0%, preferablynot more than 2.5%, more preferably not more than 2.0%, particularlypreferably not more than 1.5%. In the propylene block copolymer of theinvention, it is desired that the amount of the 23° C.-decane-solublecomponent is not more than 50%, preferably not more than 30%, morepreferably not more than 20%, particularly preferably not more than 15%.

The amount of the 23° C.-decane-soluble component in the propylenepolymer or the propylene block copolymer of the invention is measured asfollows. In a 1-liter flask equipped with a stirring device is charged 3g of a polymer sample, 20 mg of 2,6-di-tert-butyl-4-methylphenol and 500ml of n-decane, and the flask is heated in an oil bath of 145° C. todissolve the polymer sample. After the polymer sample is dissolved, theflask is cooled to room temperature over about 8 hours and then kept for8 hours in an water bath of 23° C. The n-decane suspension containingthe precipitated polymer and the dissolved polymer is separated byfilteration on a glass filter of G-4 (or G-2). The resulting solution isdried at 150° C. and 10 mmHg until its weight becomes unvaried, and theweight is measured. The weight thus measured is the amount of thepolymer component soluble in the above-mentioned mixture solvent, andthe amount is calculated as percentage to the weight of the samplepolymer.

The boiled heptane-insoluble component in the propylene polymer of theinvention desirably has a semi-crystallization period at 135° C. of notlonger than 500 seconds, preferably not longer than 100 seconds, morepreferably not longer than 80 seconds, particularly preferably notlonger than 70 seconds. The 23° C.-decane-insoluble component in thepropylene block copolymer of the invention desirably has asemi-crystallization period at 135° C. of not longer than 500 seconds,preferably not longer than 100 seconds, more preferably not longer than80 seconds, particularly preferably not longer than 70 seconds.

The semi-crystallization period at 135° C. of the boiledheptane-insoluble component in the propylene polymer or the propyleneblock copolymer is measured as follows. That is, a relation between theexotherm caused by the crystallization at 135° C. of the boiledheptane-insoluble component of the polymer and the period required forthe crystallization is measured by the use of a differential calorimeter(produced by Perkin Elmer Co.), and the period of time necessary for theexotherm to reach 50% of the whole exotherm is determined as thesemi-crystallization period.

In the propylene polymer of the invention, it is desired that adifference between the melting point of the boiled heptane-insolublecomponent and the crystallization temperature thereof is not more than45° C., preferably not more than 43° C., particularly preferably notmore than 40° C. In the propylene block copolymer of the invention, itis desired that a difference between the melting point of the boiledheptane-insoluble component and the crystallization temperature thereofis not more than 45° C., preferably not more than 43° C., particularlypreferably not more than 40° C.

The propylene polymer of the invention desirably has an intrinsicviscosity [η], as measured in decalin at 135° C., of usually 30 to 0.001dl/g, preferably 10 to 0.01 dl/g, particularly preferably 5 to 0.05dl/g. The propylene block copolymer of the invention desirably has anintrinsic viscosity [η], as measured in decalin at 135° C., of usually30 to 0.001 dl/g, preferably 10 to 0.01 dl/g, particularly preferably 8to 0.05 dl/g.

The propylene polymer of the invention mentioned as above can beprepared, for example, by a process comprising polymerizing propylene inthe presence of a catalyst for olefin polymerization (i.e., olefinpolymerization catalyst) formed from:

[Ia] a solid titanium catalyst component (a) containing magnesium,titanium, halogen and an electron donor as essential components;

[II] an organometallic catalyst component (b); and

[III] a silicon compound represented by the following formula (iii) or acompound having at least two ether linkages existing via plurality ofatoms:

R^(a) _(n)—Si—(OR^(b))_(4−n)   (iii)

wherein, n is 1, 2 or 3; when n is 1, R^(a) is a secondary or a tertiaryhydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or a tertiary hydrocarbon group, Ra may be the same ordifferent, and R^(b) is a hydrocarbon group of 1 to 4 carbon atoms; andwhen 4−n is 2 or 3, R^(b) may be the same or different.

The olefin polymerization catalyst used in the above process ispreferably formed from:

[Ib] a prepolymerized catalyst obtained by prepolymerizing at least oneolefin selected from olefins represented by the following formula (i) or(ii) in the presence of (a) a solid titanium catalyst componentcontaining magnesium, titanium, halogen and an electron donor asessential components and (b) an organometallic catalyst component;

H₂C═CH—X   (i)

H₂C═CH—CH₂—X   (ii)

wherein X is a cycloalkyl group, an aryl group or

M is carbon or silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group;

[II] the organometallic catalyst component (b); and

[III] the silicon-compound represented by the above-mentioned formula(iii) or the compound having at least two ether linkages existing viaplurality of atoms.

The propylene block copolymer of the invention can be prepared, forexample, by a process comprising a first polymerization stage forhomopolymerizing propylene or copolymerizing propylene with ethyleneand/or olefin of 4 to 10 carbon atoms to prepare a crystalline polymer(crystalline polypropylene portion) and a second polymerization stagefor copolymerizing ethylene with two or more monomers selected fromolefins of 3 to 20 carbon atoms to prepare a low-crystalline copolymer(low-crystalline copolymer portion) or a non-crystalline copolymer(non-crystalline copolymer portion), in the presence of a catalyst forolefin polymerization (i.e., olefin polymerization catalyst) formedfrom:

[Ia] the solid titanium catalyst component (a) containing magnesium,titanium, halogen and an electron donor as essential components;

[II] the organometallic catalyst component (b); and

[III] the silicon compound represented by the above-mentioned formula(iii) or the compound having at least two ether linkages existing viaplurality of atoms.

The olefin polymerization catalyst used in the above process ispreferably formed from:

[Ib] the prepolymerized catalyst obtained by prepolymerizing at leastone olefin selected from olefins represented by the above-mentionedformula (i) or (ii) in the presence of (a) the solid titanium catalystcomponent containing magnesium, titanium, halogen and an electron donoras essential components and (b) the organometallic catalyst component;

[II] the organometallic catalyst component (b); and

[III] the silicon compound catalyst component represented by theabove-mentioned formula (iii) or the compound having at least two etherlinkages existing via plurality of atoms.

Each of FIG. 1 and FIG. 2 illustrates steps of a process for preparingthe olefin polymerization catalyst which is used for preparing thepropylene polymer or the propylene block copolymer of the presentinvention.

Each components for forming the olefin polymerization catalyst used forpreparing the propylene polymer or the propylene block copolymer of theinvention are described in detail hereinafter.

The solid titanium catalyst component (a) can be prepared by bringing amagnesium compound, a titanium compound and an electron donor describedbelow into contact with each other.

The titanium compound used for preparing the solid titanium catalystcomponent (a) is, for example, a tetravalent titanium compoundrepresented by the following formula:

Ti(OR)_(g)X_(4−g)

wherein R is a hydrocarbon group, X is a halogen atom, and g is a numbersatisfying the condition of 0≦g≦4.

Concrete examples of the titanium compounds include:

titanium tetrahalide such as TiCl₄, TiBr₄ and TiI₄;

alkoxytitanium trihalide such as Ti(OCH₃)Cl₃, Ti(OC₂H₅)Cl₃,Ti(On-C₄H₉)Cl₃, Ti(OC₂H₅)Br₃ and Ti(O-iso-C₄H₉)Br₃;

dialkoxytitanium dihalide such as Ti(OCH₃)₂Cl₂, Ti(OC₂H₅)₂Cl₂,Ti(On—C₄H₉)₂Cl₂ and Ti(OC₂H₅)₂Br₂;

trialkoxytitanium monohalide such as Ti(OCH₃)₃Cl, ti(OC₂H₅)₃Cl,Ti(On-C₄H₉)₃Cl and Ti(OC₂H₅)₃Br; and

tetraalkoxytitanium such as Ti(OCH₃)₄, Ti(OC₂H₅)₄, Ti(On-C₄H₉)₄,Ti(O-iso-C₄H₉)₄ and Ti(O-2-ethylhexyl).

Of the above-exemplified compounds, preferred are halogen-containingcompounds, more preferred are titanium tetrahalides, and particularlypreferred is titanium tetrachloride. These titanium compounds may beused singly or in combination. Further, they may be diluted inhydrocarbon compounds or halogenated hydrocarbon compounds.

The magnesium compound used for preparing the solid titanium catalystcomponent (a) includes a magnesium compound having reduction propertiesand a magnesium compound having no reduction properties.

The magnesium compound having reduction properties is, for example, amagnesium compound having a magnesium-to-carbon bond or amagnesium-to-hydrogen bond. Concrete examples of the magnesium compoundhaving reduction properties include dimethylmagnesium, diethylmagnesium,dipropylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium,didecylmagnesium, ethylmagnesium chloride, propylmagnesium chloride,butylmagnesium chloride, hexylmagnesium chloride, amylmagnesiumchloride, butylethoxylmagnesium, ethylbutylmagnesium and butylmagnsiumhydride. These magnesium compounds may be used singly or may be used incombination with organometallic compounds described later to formcomplex compounds. Further, these magnesium compounds may be liquid orsolid, and may be derived by causing metallic magnesium to react with acompound corresponding to the metallic magnesium. Furthermore, they maybe derived from metallic magnesium by the above method during thepreparation of the catalyst.

Concrete examples of the magnesium compound having no reductionproperties include magnesium halide such as magnesium chloride,magnesium bromide, magnesium iodide and magnesium fluoride;alkoxymagnesium halide such as methoxylmagnesium chloride,ethoxymagnesium chloride, isopropoxymagnesium chloride, butoxymagnesiumchloride and octoxymagnesium chloride; allyloxymagnesium halide such asphenoxymagnesium chloride and methylphenoxymagnesium chloride;alkoxymagnesium such as ethoxymagnesium, isopropoxymagnesiumbutoxymagnesium, n-octoxymagnesium and 2-ethylhexoxymagnesium;allyloxymagnesium such as phenoxymagnesium and dimethylphenoxymagnesium;and manesium carboxylate such as magnesium laurate and magnesiumstearate.

These magnesium compounds having no reduction properties may be thosederived from the above-mentioned magnesium compounds having reductionproperties or those derived during the catalyst component preparationstage. In order to derive the magnesium compound having no reductionproperties from the magnesium compound having reduction properties, themagnesium compound having reduction properties is brought into contactwith halogen, a polysiloxane compound, a halogen-containing silanecompound, a halogen-containing aluminum compound, a compound having anactive carbon-to-oxygen bond such as alcohol, ester, ketone andaldehyde.

As the magnesium compound, there can be used complex compounds orcomposite compounds of the above-mentioned magnesium compounds having ornot having reduction properties with other metals, or mixtures of theabove-mentioned magnesium compounds having or not having reductionproperties with other metallic compounds. Further, these compounds maybe used in combination of two or more kinds.

Other various magnesium compounds than the above-mentioned ones can beused for preparing the solid titanium catalyst component (a), but it ispreferred that the magnesium compound takes a form of ahalogen-containing magnesium compound in the solid titanium catalystcomponent (a) finally obtained. Accordingly, if a magnesium compoundcontaining no halogen is used, the compound is preferably brought intocontact with a halogen-containing compound in the course of the catalystpreparation.

Of the above-mentioned magnesium compounds, preferred are magnesiumcompounds having no reduction properties. More preferred arehalogen-containing magnesium compounds. Particularly preferred aremagnesium chloride, alkoxymagnesium chloride and allyloxymagnesiumchloride.

The solid titanium catalyst component (a) used in the invention isformed by bringing such a magnesium compound as mentioned above intocontact with the aforesaid titanium compound and an electron donor.

Concrete examples of the electron donor employable for preparing thesolid titanium catalyst component (a) include:

amines such as methylamine, ethylamine, dimethylamine, diethylamine,ethylenediamine, tetramethylenediamine, hexamethylenediamine,tributylamine and tribenzylamine;

pyrroles such as pyrrole, methylpyrrole and dimethylpyrrole;

pyrroline;

pyrrolidine;

indole;

pyridines such as pyridine, methylpyridine, ethylpyridine,propylpyridine, dimethylpyridine, ethylmethylpyridine,trimethylpyridine, phenylpyridine, benzylpyridine and pyridine chloride;

nitrogen-containing cyclic compounds such as piperidines, quinolines andisoquinolines;

oxygen-containing cyclic compounds such as tetrahydrofuran, 1,4-cineol,1,8-cineol, pinolfuran, methylfuran, dimethylfuran, diphenylfuran,benzofuran, coumaran, phthalan, tetrahydropyran, pyran and dihydropyran;

alcohols of 1 to 18 carbon atoms such as methanol, ethanol, propanol,pentanol, hexanol, octanol, 2-ethylhexanol, dodecanol, octadecylalcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumylalcohol, isopropyl alcohol and isopropylbenzyl alcohol;

phenols of 6 to 20 carbon atoms which may have lower alkyl group such asphenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol,cumylphenol and naphthol;

ketones of 3 to 15 carbon atoms such as acetone, methyl ethyl ketone,methyl isobutyl ketone, acetophenone, benzophenone, acetylacetone andbenzoquinone;

aldehydes of 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde,octylaldehyde, benzaldehyde, tolualdehyde and naphthaldehyde;

organic esters of 2 to 30 carbon atoms such as methyl formate, methylacetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate,cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate,methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethylcrotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethylbenzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexylbenzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyltoluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, n-butylmaleate, diisobutyl methylmalonate, di-n-hexyl cyclohexenecarboxylate,diethyl nadiate, diisopropyl tetrahydrophthalate, diethyl phthalate,diisobutyl phthalate, di-n-butyl phthalate, di-2-ethylhexyl phthalate,γ-butyrolactone, δ-valerolactone, coumarin, phthalide and ethylcarbonate;

acid halides of 2 to 15 carbon atoms such as acetylchloride,benzoylchloride, toluic acid chloride and anisic acid chloride;

ethers of 2 to 20 carbon atoms such as methyl ether, ethyl ether,isopropyl ether, butyl ether, amyl ether, anisole and diphenyl etherepoxy-p-menthane;

diethers such as 2-isopentyl-2-isopropyl-1,3-dimethoxypropane,2,2-isobutyl-1,3-dimethoxypropane, 2,2-isoproyl-1,3-dimethoxypropane,2-cyclohexylmethyl-2-isopropyl-1,3-dimethoxypropane,2,2-isopentyl-1,3-dimethoxypropane,2-isobutyl-2-isopropyl-1,3-dimethoxypropane,2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane,2-cyclopentyl-2-isopropyl-1,3-dimethoxypropane,2,2-dicyclopentyl-1,3-dimethoxypropane,1,2-bis-methoxymethyl-bicyclo-[2,2,1]-heptane, diphenyldimethoxysilane,isopropyl-t-butyldimethoxysilane, 2,2-diisobutyl-1,3-dimethoxyhexane and2-isopentyl-2-isopropyl-1,3-dimethoxycylohexane;

acid amides such as acetic acid amide, benzoic acid amide and toluicacid amide;

nitriles such as acetonitrile, benzonitrile and tolunitrile; and

acid anhydrides such as acetic anhydride, phthalic anhydride and benzoicanhydride.

Also employable as the electron donor is a silicon compound representedby the formula (iii) described later.

When the titanium compound, the magnesium compound and the electrondonor are brought into contact with each other, a carrier compound maybe used to prepare a solid titanium catalyst component (a) supported ona carrier.

Examples of the carrier compounds include Al₂O₃, SiO₂, B₂O₃, MgO, CaO,TiO₂, ZnO, ZnO₂, SnO₂, BaO, ThO and resins such as astyrene/divinylbenzene copolymer. Of these carrier compounds, preferredare SiO₂, Al₂O₃, MgO, ZnO and ZnO₂.

The above-mentioned components may be brought into contact with eachother in the presence of a reaction agent such as silicon, phosphorusand aluminum.

The solid titanium catalyst component (a) is prepared by bringing theaforementioned titanium compound, magnesium compound and the electrondonor into contact with each other by known methods.

Examples of the processes for preparing the solid titanium catalystcomponent (a) are briefly described below.

(1) A process comprising bringing a solution consisting of a magnesiumcompound, an electron donor and a hydrocarbon solvent into contact withan organometallic compound, after or simultaneously with precipitating asolid by bringing the solution into contact with a titanium compound.

(2) A process comprising bringing a complex composed of a magnesiumcompound and an electron donor into contact with an organometalliccompound, and then bringing the reaction product into contact with atitanium compound.

(3) A process comprising bringing a product obtained by the contact ofan inorganic carrier and an organic magnesium compound into contact witha titanium compound. In this case, the above product may be beforehandbrought into contact with a halogen-containing compound, an electrondonor and/or an organometallic compound.

(4) A process comprising obtaining an inorganic or organic carrier onwhich a magnesium compound is supported from a mixture of an inorganicor organic carrier and a solution containing a magnesium compound and anelectron donor (and further a hydrogen solvent in some cases), and thenbringing the obtained carrier into contact with a titanium compound.

(5) A process comprising bringing a solution containing a magnesiumcompound, a titanium compound and an electron donor (and further ahydrogen solvent in some cases) into contact with an inorganic ororganic carrier to obtain a solid titanium catalyst component on whichmagnesium and titanium are supported.

(6) A process comprising bringing a liquid organic magnesium compoundinto contact with a halogen-containing titanium compound. In this case,an electron donor is used at least one time.

(7) A process comprising bringing a liquid organic magnesium compoundinto contact with a halogen-containing compound, and then bringing theproduct thus obtained into contact with a titanium compound. In thiscase, an electron donor is used at least one time

(8) A process comprising bringing an alkoxy group-containing magnesiumcompound into contact with a halogen-containing titanium compound. Inthis case, an electron donor is used at least one time

(9) A process comprising bringing a complex composed of an alkoxygroup-containing magnesium compound and an electron donor into contactwith a titanium compound.

(10) A process comprising bringing a complex composed of an alkoxygroup-containing magnesium compound and an electron donor into contactwith an organometallic compound, and then bringing the product thusobtained into contact with a titanium compound.

(11) A process comprising bringing a magnesium compound, an electrondonor and a titanium compound into contact with each other in anoptional order. In this reaction, each components may be pretreated withan electron donor and/or a reaction assistant such as an organometalliccompound or a halogen-containing silicon compound. In this case, anelectron donor is preferably used at least one time

(12) A process comprising bringing a liquid magnesium compound nothaving reducing ability into contact with a liquid titanium compound, ifnecessary in the presence of an electron donor, to precipitate a solidmagnesium/titanium complex compound.

(13) A process comprising further bringing the reaction product obtainedin the above process (12) into contact with an titanium compound.

(14) A process comprising further bringing the reaction product obtainedin the above process (11) or (12) into contact with an electron donorand a titanium compound.

(15) A process comprising pulverizing a magnesium compound and atitanium compound (and if necessary an electron donor) to obtain a solidproduct, and treating the solid product with either halogen, a halogencompound or aromatic hydrocarbon. This process may include a step ofpulverizing only a magnesium compound, a step of pulverizing a complexcompound composed of a magnesium compound and an electron donor, or astep of pulverizing a magnesium compound and a titanium compound.Further, after the pulverization, the solid product may be subjected toa pretreatment with a reaction assistant and then subjected to atreatment with halogen or the like. Examples of the reaction assistantsinclude an organometallic compound and a halogen-containing siliconcompound.

(16) A process comprising pulverizing a magnesium compound, and thenbringing the pulverized magnesium compound into contact with a titaniumcompound. In this case, an electron donor or a reaction assistant may beused in the pulverization stage and/or the contacting reaction stage.

(17) A process comprising treating the compound obtained in any of theabove processes (11) to (16) with halogen, a halogen compound oraromatic hydrocarbon.

(18) A process comprising bringing the reaction product obtained by thecontact of a metal oxide, an organic magnesium compound and ahalogen-containing compound into contact with a titanium compound and ifnecessary an electron donor.

(19) A process comprising bringing a magnesium compound such as amagnesium salt of organic acid, alkoxymagnesium or aryloxymagnesium intocontact with a titanium compound and/or halogen-containing hydrocarbonand if necessary an electron donor.

(20) A process comprising bringing a hydrocarbon solution containing atleast a magnesium compound and alkoxytitanium into contact with atitanium compound and/or an electron donor. In this case, ahalogen-containing compound such as a halogen-containing siliconcompound may be further brought into contact therewith, if necessary.

(21) A process comprising bringing a liquid magnesium compound nothaving reducing ability into contact with an organometallic compound soas to precipitate a solid magnesium/metal (aluminum) complex compound,and then bringing the resulting compound into contact with an electrondonor and a titanium compound.

The amount of each component used in the preparation of the solidtitanium catalyst component (a) differs from each preparation method,and can not be defined in general. However, for example, the electrondonor is used in an amount 0.01 to 10 mol, preferably 0.1 to 5 mol, andthe titanium compound is used in an amount of 0.01 to 1000 mol,preferably 0.1 to 200 mol, both based on 1 mol of the magnesiumcompound.

The solid titanium catalyst component (a) thus obtained containstitanium, magnesium, halogen and an electron donor as its essentialingredients.

In the solid titanium catalyst component (a), a ratio ofhalogen/titanium (atomic ratio) is about 2 to 200, preferably about 4 to100, the a ratio of electron donor/titanium (molar ratio) is about 0.01to 100, preferably about 0.02 to 10 and, a ratio of magnesium/titanium(atomic ratio) is 1 to 100, preferably 2 to 50.

The solid titanium catalyst component (a) (catalyst component [Ia]) isdesirably used as a prepolymerized catalyst component [Ib] obtained byprepolymerization of olefin in the presence of said solid titaniumcatalyst component (a) and the following organometallic catalystcomponent (b)

The organometallic catalyst component (b) used in the preparation of theprepolymerized catalyst component [Ib] includes a organometalliccompound of the metals belonging to the Group I to III of the periodictable, in concrete, such compounds as mentioned below;

organoaluminum compounds represented by the following formula (b-i)

R¹ _(m)Al(OR²)_(n)H_(p)X_(q)  (b-1)

wherein R¹ and R² may be the same or different and representindependently a hydrocarbon group having normally 1 to 15 carbon atoms,preferably 1 to 4 carbon atoms; X is halogen; and m, n, p and q arenumbers satisfying 0<m≦3, 0≦n<3, 0≦p<3, 0≦q<3 and m+n+p+q=3;

complex alkyl compounds of aluminum with Group I metals of the periodictable, represented by the following formula (b-2)

M¹AlR¹ ₄   (b-2)

wherein M¹ is Li, Na or K and R¹ is as defined above; and

dialkyl compounds of Group II or III metals represented by the followingformula

R¹R²M²   (b-3)

wherein R¹ and R² are as defined above, and M² is Mg, Zn or Cd.

Examples of the organoaluminum compounds having the formula (b-1)include:

compounds having the general formula of R¹ _(m)Al(OR²)_(3−m) wherein R¹and R² are as defined above, and m is a number preferably satisfying1.5≦m≦3;

compounds having the general formula of R¹ _(m)AlX_(3−m) wherein R¹ andX are as defined above, and m is a number preferably satisfying 0<m<3;

compounds having the general formula of R¹ _(m)AlH_(3−m) wherein R¹ isas defined above, and m is a number preferably satisfying 2≦m<3; and

compounds having the general formula of R¹ _(m)Al(OR²)_(n) X_(q) whereinR¹, R² and X are as defined above, and m, n and q are numbers satisfying0<m≦3, 0≦n<3, 0≦q<3 and m+n+q=3.

Concrete examples of the organoaluminum compounds having the formula(b-1) include

trialkylaluminum compounds such as triethylaluminum andtributylaluminum;

trialkenylaluminum compounds such as triisoprenylaluminum;

dialkylaluminum alkoxides such as diethylaluminum ethoxide anddibutylaluminum butoxide;

alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide andbutylaluminum sesquibutoxide;

partially alkoxylated alkylaluminum compounds such as those having anaverage composition represented by, for example, the formula of R¹_(2.5)Al(OR²)_(0.5);

dialkylaluminum halides such as diethylaluminum chloride,dibutylaluminum chloride and diethylaluminum bromide;

alkylaluminum sesquihalides such as ethylaluminum sesquichloride,butylaluminum sesquichloride and ethylaluminum sesquibromide;

partially halogenated alkylaluminum compounds such as alkylaluminumdihalides such as ethylaluminum dichloride, propylaluminum dichlorideand butylaluminum dibromide;

dialkylaluminum hydrides such as diethylaluminum hydride anddibutylaluminum hydride;

partially hydrogenated alkylaluminum compounds such as alkylaluminumdihydride, for example, ethylaluminum dihydride and propylaluminumdihydride; and

partially alkoxylated and halogenated alkylaluminum compounds such asethylaluminum ethoxychloride, butylaluminum butoxychloride andethylaluminum ethoxybromide.

Furthermore, the organoaluminum compounds similar to the above-mentionedcompounds represented by formula (b-1) include organoaluminum compoundsin which two or more aluminum atoms are bonded together via, forexample, an oxygen atom or a nitrogen atom. Concrete examples of suchcompounds are as follows:

(C₂H₅)₂AlOAl(C₂H₅)₂,

(C₄H₉)₂AlOAl(C₄H₉)₂,

and

and methylaluminoxane.

Examples of the organoaluminum compounds having the formula (b-2)include

LiAl(C₂H₅)₄,

and

LiAl(C₇H₁₅)₄.

Among the above-exemplified compounds, preferred are organoaluminumcompounds.

The olefin used in the preparation of the prepolymerization catalystcomponent [Ib] includes the compound represented by the above-mentionedformula (i) or (ii), concretely, olefins having a branched structuresuch as 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene,4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene,4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene,allylnaphthalene, allylnorbornene, stylene, dimethylstylenes,vinylnaphthalene, allyltoluenes, allylbenzene, vinylcyclohexane,vinylcyclopentane, vinylcycloheptane and allyltrialkylsilanes. Of these,preferred are 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-hexene,vinylcyclohexane, allyltrimethylsilane and dimethylstylene, morepreferred are 3-methyl-1-butene, vinylcyclohexane andallyltrimethylsilane, and particularly preferred is 3-methyl-1-butene.

Furthermore, linear chain olefins such as ethylene, propylene, 1-butene,1-octene, 1-hexadecene and 1-eicocene may be used in combination withthe above-mentioned branched olefins.

The prepolymerization can be carried out in the presence of considerablyhigher-concentration of catalyst compared to the catalyst concentrationin the system of propylene polymerization.

In the pre-polymerization, the solid titanium catalyst component (a) isdesirably used in aconcentration of normally about 0.01 to 200 mmol,preferably about 0.05 to 100 mmol, in terms of titanium atom, based on 1liter of the later-described inert hydrocarbon solvent.

The organometallic catalyst component (b) is used in an amount so as toproduce a polymer of 0.1 to 1000 g, preferably 0.3 to 500 g per 1 gramof the solid titanium catalyst component (a), and is used in aconcentration of normally about 0.1 to 100 mmol, preferably about 0.5 to50 mmol based on 1 mol of titanium atom in the solid titanium catalystcomponent (a).

In the prepolymerization, an electron donor may be optionally used withthe solid titanium catalyst component (a) and organometallic catalystcomponent (b). The electron donor employable in the prepolymerizationinclude, concretely, the aforementioned electron donor used in thepreparation of the solid titanium catalyst component (a), thelater-described silicon compound represented by the formula (iii), acompound having at least two ether linkages exsisting via plurality ofatoms, and an organosilicon compound represented by the followingformula (c-i);

R_(n)Si(OR′)_(4−n)   (c-i)

wherein each of R and R′ is a hydrocarbon group, and n is a numbersatisfying the condition of 0<n<4.

The later-described silicon compounds represented by the formula (iii)are not included in the organosilicon compounds represented by thisformula (c-i).

Concrete examples of the organosilicon compounds represented by theabove formula (c-i) include:

trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane,dimethyldiethoxysilane, diisopropyldimethoxysilane,diphenyldimethoxysilane, phenylmethyldimethoxysilane,diphenyldiethoxysilane, bis-o-tolyldimethoxysilane,bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane,bis-p-tolyldiethoxysilane, bis-ethylphenyldimethoxysilane,ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane,methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane,decyltriethoxysilane, phenyltrimethoxysilane,γ-chloropropyltrimethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, vinyltriethoxysilane, n-butyltriethoxysilane,phenyltriethoxysilane, γ-aminopropyltriethoxysilane,chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane,ethyl silicate, butyl silicate, trimethylphenoxysilane,methyltriallyoxysilane, vinyltris(β-methoxyethoxysilane),vinyltriacetoxysilane and dimethyltetraethoxysiloxane.

The above-mentioned electron donors (c) may be used in combination oftwo or more kinds.

In the case of using an electron donor in the prepolymerization, theamount of the electron donor is in the range of 0.1 to 50 mol,preferably 0.5 to 30 mol, more preferably 1 to 10 mol, per 1 mol totitanium atom contained in the solid titanium catalyst component (a).

The prepolymerization is preferably carried out under a mild conditionby adding the olefin represented by the above formula (i) or (ii) andthe above mentioned catalyst components into an inert hydrocarbonsolvent.

Concrete examples of the above-mentioned inert solvents include:

aliphatic hydrocarbons such as propane, butane, pentane, hexane,heptane, octane, decane, dodecane and kerosine;

alicyclic hydrocarbons such as cyclopentane, cyclohexane andmethylcyclopentane;

aromatic hydrocarbons such as benzene, toluene and xylene;

halogenated hydrocarbons such as ethylene chloride and chlorobenzene;and

mixtures of these hydrocarbons.

Of these inert hydrocarbon media, preferably used are aliphatichydrocarbons.

The reaction temperature in the prepolymerization is a temperature atwhich the resulting prepolymer is not substantially dissolved in theinert hydrocarbon solvent, and is desired to be in the range of usuallyabout −20 to +100° C., preferably about −20 to +80° C., more preferably−10 to +40° C. A molecular weight regulator such as hydrogen can be usedin the prepolymerization.

The prepolymerization is desirably carried out so as to obtain about 0.1to 1000 g, preferably about 0.3 to 500 g of polymer, per 1 g of theabove mentioned solid titanium catalyst component (a). When the amountof the polymer produced in the prepolymerization is too much, theproductive efficiency of the (co)polymer produced in the mainpolymerization is lowered, and the films formed from the resulting(co)polymer have a tendency to create a fish-eye.

The prepolymerization can be carried out by any process of a batchprocess and a continuous process.

The olefin polymerization catalyst used for the preparation of thepropylene polymer or propylene block copolymer according to the presentinvention is formed from the above mentioned solid titanium catalystcomponent [Ia] or the prepolymerized catalyst component [Ib], anorganometallic catalyst component [II], and [III] a silicon compound ora compound having at least two ether linkages exsisting via plurality ofatoms.

As the organometallic catalyst component [II], the aforementionedorganometallic catalyst component (b) used in the preparation of theprepolymerized catalyst component [Ib] can be employed.

The silicon compound [III] is the compound represented by the followingformula (iii);

R^(a) _(n)—Si—(OR^(b))_(4−n)   (iii)

wherein, n is 1, 2 or 3; when n is 1, R^(a) is a secondary or a tertiaryhydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or a tertiary hydrocarbon group, R^(a) may be the same ordifferent, and R^(b) is a hydrocarbon group of 1 to 4 carbon atoms; andwhen 4−n is 2 or 3, R^(b) may be the same or different.

In the silicon compound represented by the formula (iii), the secondaryor the tertiary hydrocarbon group includes cyclopentyl, cyclopentenyland cyclopentadienyl, and substituted thereof, and the hydrocarbon groupin which the carbon adjacent to Si is a secondary or tertiary.

More concretely, the substituted cyclopentyl group includes cyclopentylgroup having alkyl group such as 2-methylcyclopentyl,3-methylcyclopentyl, 2-ethylcyclopentyl, 2-n-butylcyclopentyl,2,3-dimethylcyclopentyl, 2,4-dimethylcyclopentyl,2,5-dimethylcyclopentyl, 2,3-diethylcyclopentyl,2,3,4-trimethylcyclopentyl, 2,3,5-trimethylcyclopentyl,2,3,4-triethylcyclopentyl, tetramethylcyclopentyl andtetraethylcyclopentyl;

the substituted cyclopentenyl group includes cyclopentenyl group havingalkyl group such as 2-methylcyclopentenyl, 3-methylcyclopentenyl,2-ethylcyclopentenyl, 2-n-butylcyclopentenyl, 2,3-dimethylcyclopentenyl,2,4-dimethylcyclopentenyl, 2,5-dimethylcyclopentenyl,2,3,4-trimethylcyclopentenyl, 2,3,5-trimethylcyclopentenyl,2,3,4-triethylcyclopentenyl, tetramethylcyclopentenyl andtetraethylcyclopentenyl;

the substituted cyclopentadienyl group includes cyclopentadienyl grouphaving alkyl group such as 2-methylcyclopentadienyl,3-methylcyclopentadienyl, 2-ethylcyclopentadienyl,2-n-butylcyclopentadienyl, 2,3-dimethylcyclopentadienyl,2,4-dimethylcyclopentadienyl, 2,5-dimethylcyclopentadienyl,2,3-diethylcyclopentadienyl, 2,3,4-trimethylcyclopentadienyl,2,3,5-trimethylcyclopentadienyl, 2,3,4-triethylcyclopentadienyl,2,3,4,5-tetramethylcyclopentadienyl, 2,3,4,5-tetraethylcyclopentadienyl,1,2,3,4,5-pentamethylcyclopentadienyl and1,2,3,4,5-pentaethylcyclopentadienyl.

The hydrocarbon group in which the carbon adjacent to Si is a secondaryincludes i-propyl, s-butyl, s-amyl and α-benzyl; and

the hydrocarbon group in which the carbon adjacent to Si is a tertiaryincludes t-butyl, t-amyl, α,α′-diemethylbenzyl and admantyl.

When n is 1, the silicon compound represented by the formula (iii)includes trialkoxysilanes such as cyclopentyltrimethoxysilane,2-methylcyclopentyltrimethoxysilane,2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,iso-butyltriethoxysilane, t-butyltriethoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,2-norbornanetrimethoxysilane, and 2-norbornanetriethoxysilane;

when n is 2, the silicon compound represented by the formula (iii)includes dialkoxysilanes such as dicyclopentyldiethoxysilane,t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane,t-amylmethyldiethoxysilane, dicyclohexyldimethoxysilane,cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, and2-norbornanemethyldimethoxysilane.

When n is 2, the silicon compound represented by the formula (iii) ispreferably dimethoxy compound represented by the following formula (iv);

wherein, R^(a) and R^(c) are each independently a cyclopentyl group, asubstituted cyclopentyl group, a cyclopentenyl group, a substitutedcyclopentenyl group, cyclopentadienyl group, a substitutedcyclopentadienyl group or a hydrocarbon group whose carbon adjacent toSi is a secondary carbon or a tertiary carbon.

The silicon compound represented by the formula (iv) includes, forexample, dicyclopentyldimethoxysilane, dicyclopentenyldimethoxyxilane,dicyclopentadienyldimethoxyxilane, di-t-butyldimethoxysilane,di-(2-methylcyclopentyl)dimethoxysilane,di-(3-methylcyclopentyl)dimethoxysilane,di-(2-ethylcyclopentyl)dimethoxysilane, di-(2,3-dimethylcyclopentyl)dimethoxysilane, di-(2,4-dimethylcyclopentyl)dimethoxysilane,di-(2,5-dimethylcyclopentyl)dimethoxysilane,di-(2,3-diethylcyclopentyl)dimethoxysilane,di-(2,3,4-trimethylcyclopentyl)dimethoxysilane,di-(2,3,5-trimethylcyclopentyl)dimethoxysilane,di-(2,3,4-triethylcyclopentyl)dimethoxysilane,di-(tetramethylcyclopentyl)dimethoxysilane,di-(tetraethylcyclopentyl)dimethoxysilane,di-(2-methylcyclopentenyl)dimethoxysilane,di-(3-ethylcyclopentenyl)dimethoxysilane,di-(2-ethylcyclopentenyl)dimethoxysilane,di-(2-n-butylcyclopentenyl)dimethoxysilane,di-(2,3-dimethylcyclopentenyl)dimethoxysilane,di-(2,4-dimethylcyclopentenyl)dimethoxysilane,di-(2,5-diethylcyclopentenyl)dimethoxysilane,di-(2,3,4-trimethylcyclopentenyl)dimethoxysilane,di-(2,3,5-trimethylcyclopentenyl)dimethoxysilane,di-(2,3,4-triethylcyclopentenyl)dimethoxysilane,di-(tetramethylcyclopentenyl)dimethoxysilane,di-(tetraethylcyclopentenyl)dimethoxysilane,di-(2-methylcyclopentadienyl)dimethoxysilane,di-(3-methylcyclopentadienyl)dimethoxysilane,di-(2-ethylcyclopentadienyl)dimethoxysilane,di-(2-n-butylcyclopentadienyl)dimethoxysilane,di-(2,3-dimethylcyclopentadienyl)dimethoxysilane,di-(2,4-dimethylcyclopentadienyl)dimethoxysilane,di-(2,5-dimethylcyclopentadienyl)dimethoxysilane,di-(2,3-diethylcyclopentadienyl)dimethoxysilane,di-(2,3,4-trimethylcyclopentadienyl)dimethoxysilane,di-(2,3,5-trimethylcyclopentadienyl)dimethoxysilane,di-(2,3,4-triethylcyclopentadienyl)dimethoxysilane,di-(2,3,4,5-tetramethylcyclopentadienyl)dimethoxysilane,di-(2,3,4,5-tetraethylcyclopentadienyl)dimethoxysilane,di-(1,2,3,4,5-pentamethylcyclopentadienyl)dimethoxysilane,di-(1,2,3,4,5-pentaethylcyclopentadienyl)dimethoxysilane,di-t-amyl-dimethoxysilane, di-(α,α′-dimethylbenzyl)dimethoxysilane,di-(admantyl)dimethoxysilane, admantyl-t-butyldimethoxysilane,cyclopentyl-t-butyldimethoxysilane, di-isopropyldimethoxysilane,di-s-butyldimethoxysilane, di-s-amyldimethoxysilane, andisopropyl-s-butyldimethoxysilane.

When n is 3, the silicon compound represented by the formula (iii)includes monoalkoxysilanes such as tricyclopentylmethoxysilane,tricyclopentylethoxysilane, dicyclopentylmethylmethoxysilane,dicyclopentylethylmethoxysilane, dicyclopentylmethylethoxysilane,dicyclopentyldimethylmethoxysilane, cyclopentyldiethylmethoxysilane, andcyclopentyldimethylethoxysilane.

Of these, preferred are dimethoxysilanes, particularly preferred aredimethoxysilanes represented by the formula (iv), to be concretely,preferably used is dicyclopentyldimethoxysilane,di-t-butyldimethoxysilane, di-(2-methylcyclopentyl)dimethoxysilane,di-(3-methylcyclopentyl)dimethoxysilane or do-t-amyldimethoxysilane.

In the compound (hereinafter sometimes referred as “polyether compound”)having at least two ether linkages existing via plurality of atoms usedin the present invention, the atoms existing between these etherlinkages are at least one kind of atom selected from the groupconsisting of carbon, silicon, oxygen, sulfur, phosphorus and boron, andthe number of the atoms are not less than two. Of these compoundsmentioned above, preferred are those in which a relatively bulkysubstituent attaches to the atom intermediately existing between theether linkages. The relatively bulky substituent concretely means thesubstituent having 2 or more of carbon atoms, preferably the substituenthaving a structure of linear, branched or cyclic contaning 3 or more ofcarbon atoms, particularly the substituent having branched or cyclicstructure. Further, preferred is a compound containing plurality of,preferably 3 to 20, more preferably 3 to 10, particularly prefereably 3to 7 carbon atoms in the atoms intermediately existing between at leasttwo ether linkages.

Such polyether compound as mentioned above includes, for example, thoserepresented by the following formula

wherein n is an integer of 2≦n≦10, R¹-R²⁶ are each a substituent havingat least one element selected from among carbon, hydrogen, oxygen,halogen, nitrogen, sulfur, phosphorus, boron and silicon, any of R¹-R²⁶,preferably R¹-R^(2n) may form, together a ring other than a benzenering, and the main chain of the compound may contain atoms other thancarbon.

The polyether compound as illustrated above includes2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane,2-butyl-1,3-dimethoxypropane, 2-s-butyl-1,3-dimethoxypropane,2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane,2-cumyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane,2-(2-cyclohexylethyl)-1,3-dimethoxypropane,2-(p-chlorophenyl)-1,3-dimethoxypropane,2-(diphenylmethyl)-1,3-dimethoxypropane,2-(1-naphthyl)-1,3-dimethoxypropane,2-(2-fluorophenyl)-1,3-dimethoxypropane,2-(1-decahydronaphthyl)-1,3-dimethoxypropane,2-(p-t-butylphenyl)-1,3-dimethoxypropane,2,2-dicyclohexyl-1,3-dimethoxypropane,2,2-dicyclopentyl-1,3-dimethoxypropane,2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane,2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane,2-methyl-2-propyl-1,3-dimethoxypropane,2-methyl-2-benzyl-1,3-dimethoxypropane,2-methyl-2-ethyl-1,3-dimethoxypropane,2-methyl-2-isopropyl-1,3-dimethoxypropane,2-methyl-2-phenyl-1,3-dimethoxypropane,2-methyl-2-cyclohexyl-1,3-dimethoxypropane,2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane,2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane,2-methyl-2-iso-butyl-1,3-dimethoxypropane,2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane,2,2-di-iso-butyl-1,3-dimethoxypropane,2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane,2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,2,2-di-iso-butyl-1,3-diethoxypropane,2,2-di-iso-butyl-1,3-dibutoxypropane,2-iso-butyl-2-isopropyl-1,3-dimethoxypropane,2-(1-methylbutyl)-2-isopropyl-1,3-dimethoxypropane,2-(1-methylbutyl)-2-s-butyl-1,3-dimethoxypropane,2,2-di-s-butyl-1,3-dimethoxypropane,2,2-di-t-butyl-1,3-dimethoxypropane,2,2-dineopentyl-1,3-dimethoxypropane,2-iso-propyl-2-iso-pentyl-1,3-dimethoxypropane,2-phenyl-2-isopropyl-1,3-dimethoxypropane,2-phenyl-2-s-butyl-1,3-dimethoxypropane,2-benzyl-2-isopropyl-1,3-dimethoxypropane,2-benzyl-2-s-butyl-1,3-dimethoxypropane,2-phenyl-2-benzyl-1,3-dimethoxypropane,2-cyclopentyl-2-isopropyl-1,3-dimethoxypropane,2-cyclopentyl-2-s-butyl-1,3-dimethoxypropane,2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane,2-cyclohexyl-2-s-butyl-1,3-dimethoxypropane,2-isopropyl-2-s-butyl-1,3-dimethoxypropane,2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane,2,3-diphenyl-1,4-diethoxybutane, 2,3-dicyclohexyl-1,4-diethoxybutane,2,2-dibenzyl-1,4-diethoxybutane, 2,3-dicyclohexyl-1,4-diethoxybutane,2,3-di-iso-propyl-1,4-diethoxybutane,2,2-bis(p-methylphenyl)-1,4-dimethoxybutane,2,3-bis(p-chlorophenyl)-1,4-dimethoxybutane,2,3-bis(p-fluorophenyl)-1,4-dimethoxybutane,2,4-diphenyl-1,5-dimethoxypentane, 2,5-diphenyl-1,5-dimethoxyhexane,2,4-di-iso-propyl-1,5-dimethoxypentane,2,4-di-iso-butyl-1,5-dimethoxypentane,2,4-di-iso-amyl-1,5-dimethoxypentane, 3-methoxymethyltetrahydrofuran,3-methoxymethyldioxane, 1,3-di-iso-butoxypropane,1,2-di-iso-butoxypropane, 1,2-di-iso-butoxyethane,1,3-di-iso-amyloxypropane, 1,3-di-iso-neopentyloxyethane,1,3-dineopentyloxypropane, 2,2-tetramethylene-1,3-dimethoxypropane,2,2-pentamethylene-1,3-dimethoxypropane,2,2-hexamethylene-1,3-dimethoxypropane,1,2-bis(methoxymethyl)cyclohexane, 2,8-dioxaspiro[5,5]undecane,3,7-dioxabicyclo[3,3,1]nonane, 3,7-dioxabicyclo[3,3,0]octane,3,3-di-iso-butyl-1,5-oxononane, 6,6-di-iso-butyldioxyheptane,1,1-dimethoxymethylcyclopentane, 1,1-bis(dimethoxymethyl)cyclohexane,1,1-bis(methoxymethyl)bicyclo[2,2,1]heptane,1,1-dimethoxymethylcyclopentane,2-methyl-2-methoxymethyl-1,3-dimethoxypropane,2-cyclohexyl-2-ethoxymethyl-1,3-diethoxypropane,2-cyclohexyl-2-methoxymethyl-1,3-dimethoxypropane,2,2-di-iso-butyl-1,3-dimethoxycyclohexane,2-iso-propyl-2-iso-amyl-1,3-dimethoxycyclohexane,2-cyclohexyl-2-methoxymethyl-1,3-dimethoxycyclohexane,2-iso-propyl-2-methoxymethyl-1,3-dimethoxycyclohexane,2-iso-butyl-2-methoxymethyl-1,3-dimethoxycyclohexane,2-cyclohexyl-2-ethoxymethy-1,3-diethoxycyclohexane,2-cyclohexyl-2-ethoxymethyl-1,3-dimethoxycyclohexane,2-iso-propyl-2-ethoxymethyl-1,3-diethoxycyclohexane,2-iso-propyl-2-ethoxymethyl-1,3-dimethoxycyclohexane,2,-iso-butyl-2-ethoxymethyl-1,3-diethoxycyclohexane,2-iso-butyl-2-ethoxymethyl-1,3-dimethoxycyclohexane,tris(p-methoxyphenyl)phospine, methlphenylbis(methoxymethyl)silane,diphenylbis(methoxymethyl)silane,methylcyclohexylbis(methoxymethyl)silane,di-t-butylbis(methoxymethyl)silane,cyclohexyl-t-butylbis(methoxymethyl)silane andiso-propyl-t-butylbis(methoxymethyl)silane.

Of these compounds, preferred are 1,3-diethers, espesially,2,2-di-iso-butyl-1,3-dimethoxypropane,2-iso-propyl-2-iso-pentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3dimethoxypropane and 2,2-bis(cyclohexylmethyl)1,3-dimethoxypropane.These compounds may be used either singly or in combination.

Next, processes for preparing the propylene polymer and the propyleneblock copolymer of the invention are described.

The propylene polymer of the invention can be obtained by polymerizingpropylene in the presence of the olefin polymerization catalyst formedfrom the solid titanium catalyst component [Ia], the organometalliccatalyst component [II] and the silicon compound represented by theformula (iii) or the polyether compound [III], preferably in thepresence of the olefin polymerization catalyst formed from theprepolymerized catalyst component [Ib], the organometallic catalystcomponent [II] and the silicon compound catalyst component representedby the formula (iii) or the polyether compound [III].

In the polymerization of propylene, a small amount of other olefin thanpropylene or a small amount of a diene compound may be present in thepolymerization system in addition to propylene.

Examples of the olefin other than propylene include ethylene and olefinsof 3 to 8 carbon atoms such as 1-butene, 1-pentene, 1-hexene,4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene and 3-methyl-1-butene.

Examples of the diene compound include diene compounds of 4 to 20 carbonatoms such as 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene,1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene, 4-methyl-1,4-hexadiene,5-methyl-1,4-hexadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene,6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene,6-methyl-1,6-nonadiene, 7-methyl-1, 6-nonadiene, 6-ethyl-1,6-nonadiene,7-ethyl-1,6-nonadiene, 6-methyl-1,6-decadiene, 7-methyl-1,6-decadiene,6-methyl-1,6-undecadiene, 1,7-octadiene, 1,9-decadiene, isoprene,butadiene, ethylidenenorbornene, vinylnorbornene and dicyclopentadiene.

The polymerization of propylene is generally conducted in a gas phase ora liquid phase.

When the polymerization is a slurry polymerization or a solutionpolymerization, the same inert hydrocarbon as used for preparing theaforesaid prepolymerized catalyst component [Ib] can be employed as areaction solvent.

In the polymerization system, the solid titanium catalyst component [Ia]or the prepolymerized catalyst component [Ib] is used in an amount ofusually about 0.0001 to 50 mmol, preferably about 0.001 to 10 mmol, interms of titanium atom contained in the solid titanium catalystcomponent [Ia] or contained in the prepolymerized catalyst component[Ib], per 1 liter of the polymerization volume. The organometalliccatalyst component [II] is used in such an amount that the amount of themetal atom contained in the organometallic catalyst component [II] mightbe in the range of usually about 1 to 2,000 mol, preferably about 2 to500 mol, per 1 mol of the titanium atom in the polymerization system.The silicon compound or the polyether compound [III] is used in anamount of usually about 0.001 to 50 mol, preferably about 0.01 to 20mol, per 1 mol of the metal atom in the organometallic catalystcomponent [II].

If hydrogen is used in the polymerization stage, a propylene polymerhaving a high melt flow rate can be obtained. Further, the molecularweight of the propylene polymer can be controlled by adjusting theamount of hydrogen. Even in the case of using hydrogen, the obtainedpropylene polymer of the invention is never lowered in the crystallinityand the pentad isotacticity, and moreover the catalytic activity is notreduced.

In the invention, the polymerization of propylene is carried out at atemperature of usually about −50 to 200° C., preferably about 20 to 100°C., under a pressure of usually an ordinary pressure to 100 kg/cm²,preferably about 2 to 50 kg/cm². The polymerization may be carried outeither batchwise, semi-continuously or continuously.

In this process of the invention, propylene is desirably polymerized inan amount of 3,000 to 1,000,000 g per 1 g of the solid titanium catalystcomponent (a) in the aforesaid prepolymerized catalyst component [Ib].

When a propylene polymer is prepared as above, an yield of the propylenepolymer per unit amount of the solid catalyst component can beincreased, and hence the amount of the catalyst residue (particularlyhalogen content) in the propylene polymer can be relatively reduced.Accordingly, an operation for removing the catalyst residue contained inthe propylene polymer can be omitted, and moreover in the case ofmolding the obtained propylene polymer, a mold can be easily preventedfrom occurrence of rust.

In the propylene polymer obtained as above, an amount of an amorphouscomponent (amorphous portion) is extremely small, and thereby an amountof the hydrocarbon-soluble component is also small. Accordingly, when afilm is formed from the propylene polymer, the film is low in thesurface tackiness.

The propylene polymer of the invention may be prepared in two or morepolymerization stages having different reaction conditions. In thiscase, the polymerization is carried out in a gas phase or a liquid phaseusing 2 to 10 polymerizers.

When the polymerization is a slurry polymerization or a solutionpolymerization, the same inert hydrocarbon as used for preparing theaforesaid prepolymerized catalyst component [Ib] can be employed as areaction solvent.

In this polymerization process, polymerization of propylene is conductedin at least one polymerizer among the two or more polymerizers, toprepare a polymer having an intrinsic viscosity [η] of 3 to 40 dl/g,preferably 5 to 30 dl/g, particularly preferably 7 to 25 dl/g. Thispolymerization is sometimes referred to as “A polymerization”hereinafter.

It is desired that the isotactic pentad value (pentad isotacticity) [M₅]determined by the NMR measurement of the boiled heptane-insolublecomponent in the polymer obtained in this A polymerization is in therange of 0.960 to 0.995, preferably 0.970 to 0.995, more preferably0.980 to 0.995, most preferably 0.982 to 0.995.

It is also desired that the amount of the boiled heptane-insolublecomponent in the polymer is not less than 80%, preferably not less than90%, more preferably not less than 94%, much more preferably not lessthan 95%, particularly preferably not less than 96%.

In the A polymerization, the polymer is desirably prepared in such amanner that the amount of the polymer obtained in the A polymerizationmight be in the range of 0.1 to 55%, preferably 2 to 35%, particularlypreferably 5 to 30%, based on the amount of the polymer finallyobtained.

In the case of preparing the propylene polymer using two or morepolymerizers, polymerization of propylene is also conducted in theresidual polymerizers out of the two or more polymerizers to prepare apropylene polymer having a melt flow rate of 0.1 to 500 g/10 min as afinal polymer. This polymerization is sometimes referred to as “Bpolymerization” hereinafter.

In the A polymerization and the B polymerization, the solid titaniumcatalyst component [Ia] or the prepolymerized catalyst component [Ib] isused in an amount of usually about 0.0001 to 50 mmol, preferably about0.001 to 10 mmol, in terms of titanium atom contained in the solidtitanium catalyst component [Ia] or contained in the prepolymerizedcatalyst component [Ib], per 1 liter of the polymerization volume. Theorganometallic catalyst component [II] is used in such an amount thatthe amount of the metal atom contained in the organometallic catalystcomponent [II] might be in the range of usually about 1 to 2,000 mol,preferably about 2 to 500 mol, per 1 mol of the titanium atom in thepolymerization system. The silicon compound or the polyether compound[III] is used in an amount of usually about 0.001 to 50 mol, preferablyabout 0.01 to 20 mol, per 1 mol of the metal atom in the organometalliccatalyst component [II].

If necessary, the solid titanium catalyst component [Ia] or theprepolymerized catalyst component [Ib], the organometallic catalystcomponent [II] and the silicon compound or the polyether compound [III]may be added to any of the plural polymerizers. Further, the electrondonor used in the preparation of the solid titanium catalyst component(a) and/or the organosilicon compound represented by the above formula(c-i) may be added to any of the plural polymerizers.

Further, in any of the A polymerization and the B polymerization,hydrogen may be fed or removed, whereby the molecular weight of thepropylene polymer can be easily regulated. Even in this case, theobtained propylene polymer of the invention is never lowered in thecrystallinity and the pentad isotacticity, and moreover the catalyticactivity is not reduced. The feed amount of hydrogen varies according tothe reaction conditions, but generally, the feed amount of hydrogen issuch an amount that the melt flow rate of the polymer finally obtainedmight be in the range of 0.1 to 500 g/10 min.

The value [M₅] of the boiled heptane-insoluble component is usually inthe range of 0.975 to 0.995, preferably 0.980 to 0.995, more preferably0.982 to 0.995; and the value [M₃] of the boiled heptane-insolublecomponent is usually in the range of 0.0020 to 0.0050, preferably 0.0023to 0.0045, more preferably 0.0025 to 0.0040.

In the A polymerization and the B polymerization, the polymerization ofpropylene is carried out at a temperature of usually about −50 to 200°C., preferably about 20 to 100 ° C., under a pressure of usually anordinary pressure to 100 kg/cm², preferably about 2 to 50 kg/cm². Thepolymerization may be carried out either batchwise, semi-continuously orcontinuously.

In this process of the invention, propylene is desirably polymerized inan amount of 3,000 to 100,000 g per 1 g of the solid titanium catalystcomponent (a) in the aforesaid prepolymerized catalyst component [Ib].

The propylene block copolymer of the invention can be prepared by aprocess comprising a first polymerization stage for homopolymerizingpropylene or copolymerizing propylene with ethylene and/or olefin of 4to 10 carbon atoms to prepare a crystalline polymer (crystallinepolypropylene portion) and a second polymerization stage forcopolymerizing two or more monomers selected from olefins of 2 to 20carbon atoms to prepare a low-crystalline copolymer (low-crystallinecopolymer portion) or a non-crystalline copolymer (non-crystallinecopolymer portion), in the presence of a catalyst for olefinpolymerization (i.e., olefin polymerization catalyst) formed from thesolid titanium catalyst component [Ia], the organometallic catalystcomponent [II] and the silicon compound represented by the aforesaidformula (iii) or the polyether compound (III), preferably in thepresence of the olefin polymerization catalyst formed from theprepolymerized catalyst component [Ib], the organometallic catalystcomponent [II] and the silicon compound represented by the aforesaidformula (iii) or the polyether compound [III].

In this process for preparing a propylene block copolymer, at first,homopolymerization of propylene or copolymerization of propylene withethylene and/or olefin of 4 to 10 carbon atoms is carried out in thefirst polymerization stage.

Concrete examples of the olefin of 4 to 10 carbon atoms include1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene,1-octene, 3-methyl-1-butene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, cyclopentene, cycloheptene,norbornene, 5-methyl-2-norbornene, tetracyclododecene and2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene.

In the first polymerization stage, the polymerization is carried outgenerally in a gas phase or a liquid phase.

When the polymerization is a slurry polymerization or a solutionpolymerization, the same inert hydrocarbon as used for preparing theaforesaid prepolymerized catalyst component [Ib] can be employed as areaction solvent.

In the first polymerization stage, the solid titanium catalyst component[Ia] or the prepolymerized catalyst component [Ib] is used in an amountof usually about 0.0001 to 50 mmol, preferably about 0.001 to 10 mmol,in terms of titanium atom contained in the solid titanium catalystcomponent [Ia] or contained in the prepolymerized catalyst component[Ib], per 1 liter of the polymerization volume. The organometalliccatalyst component [II] is used in such an amount that the amount of themetal atom contained in the organometallic catalyst component [II] mightbe in the range of usually about 1 to 2,000 mol, preferably about 2 to500 mol, per 1 mol of the titanium atom in the polymerization system.The silicon compound or the polyether compound [III] is used in anamount of usually about 0.001 to 50 mol, preferably about 0.01 to 20mol, per 1 mol of the metal atom in the organometallic catalystcomponent [II].

Hydrogen may be used in the first polymerization stage, whereby themolecular weight of the polymer obtained can be regulated.

In the first polymerization stage, the polymerization of propylene iscarried out at a temperature of usually about −50 to 200° C., preferablyabout 20 to 100° C., under a pressure of usually an ordinary pressure to100 kg/cm², preferably about 2 to 50 kg/cm². The polymerization may becarried out either batchwise, semi-continuously or continuously.

It is desired that a content of the constituent units derived fromethylene and/or olefin of 4 to 10 carbon atoms in the polymer obtainedin the first polymerization stage is in the range of 0 to 20% by mol,preferably 0 to 15% by mol, particularly preferably 0 to 10% by mol.

It is also desired that the polymer obtained in the first polymerizationstage has an intrinsic viscosity [η], as measured in decalin at 135° C.,of 40 to 0.001 dl/g, preferably 30 to 0.01 dl/g, particularly preferably20 to 0.05 dl/g.

In the first polymerization stage, in addition to propylene and ethyleneand/or olefin of 4 to 10 carbon atoms, a small amount of a dienecompound may be added to the polymerization system so as to introduceconstituent units derived from the diene compound into the polymerobtained in the first polymerization stage.

Examples of the diene compounds employable herein include dienecompounds of 4 to 20 carbon atoms such as 1,3-butadiene, 1,3-pentadiene,1,4-pentadiene, 1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene,4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 6-methyl-1,6-octadiene,7-methyl-1,6-octadiene, 6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene,6-butyl-1,6-octadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene,6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 6-methyl-1,6-decadiene,7-methyl-1,6-decadiene, 6-methyl-1,6-undecadiene, 1,7-octadiene,1,9-decadiene, isoprene, butadiene, ethylidenenorbornene,vinylnorbornene and dicyclopentadiene. Of these, preferred are dienecompounds of 5 to 12 carbon atoms such as 1,4-hexadiene, 1,5-hexadiene,4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 7-methyl-1,6-octadiene,ethylidenenorbornene and vinylnorbornene.

In the preparation of the propylene block copolymer according to theinvention, there is a method, for example, after the firstpolymerization stage, copolymerization of two or more monomers selectedfrom olefins of 2 to 20 carbon atoms is carried out in the presence ofthe polymer obtained in the first polymerization stage.

Examples of the olefins of 2 to 20 carbon atoms used herein includeethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene,3-methyl-1-pentene, 1-octene, 3-methyl-1-butene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, cyclopentene,cycloheptene, norbornene, 5-ethyl-2-norbornene, tetracyclododecene and2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene.Preferably used are olefins of 3 to 12 carbon atoms.

In the second polymerization stage, the polymerization is carried outgenerally in a gas phase or a liquid phase.

When the polymerization is a slurry polymerization or a solutionpolymerization, the same inert hydrocarbon as used for preparing theaforesaid prepolymerized catalyst component [Ib] can be employed as areaction solvent.

In the second polymerization stage, if necessary, the solid titaniumcatalyst component [Ia] or the prepolymerized catalyst component [Ib],organometallic catalyst component [II], and the silicon compound or thepolyether compound [III] may be added. The solid titanium catalystcomponent [Ia] or the prepolymerized catalyst component [Ib] may beadded in an amount of usually about 0.0001 to 50 mmol, preferably about0.001 to 10 mmol, in terms of titanium atom contained in the solidtitanium catalyst component [Ia] or contained in the prepolymerizedcatalyst component [Ib], per 1 liter of the polymerization volume. Theorganometallic catalyst component [II] may be added in such an amountthat the amount of the metal atom contained in the organometalliccatalyst component [II] might be in the range of usually about 1 to2,000 mol, preferably about 2 to 500 mol, per 1 mol of the titanium atomadded in the polymerization system. The silicon compound or thepolyether compound [III] may be used in an amount of usually about 0.001to 50 mol, preferably about 0.01 to 20 mol, per 1 mol of the metal atomin the organometallic catalyst component [II].

If hydrogen is used in the second polymerization system, the molecularweight of resulting low-crystalline or non-crystalline olefin copolymercan be regulated by adjusting the amount of hydrogen.

In the second polymerization stage, the polymerization of propylene iscarried out at a temperature of usually about −50 to 200° C., preferablyabout 20 to 100° C., under a pressure of usually an ordinary pressure to100 kg/cm², preferably about 2 to 50 kg/cm². The polymerization may becarried out either batchwise, semi-continuously or continuously.

In the second polymerization stage, small amount of diene compound maybe introduced into the reaction system as similar to the above-mentionedfirst polymerization stage. Further, the electron donor used in thepreparation of the solid titanium catalyst component (a) and/or theorganosilicon compound represented by the above formula (c-i) may beadded to any of the first and second polymerization stage.

When a propylene block copolymer is prepared as above, an yield of thepropylene block copolymer per unit amount of the solid catalystcomponent can be increased, and hence the amount of the catalyst residue(particularly halogen content) in the propylene block copolymer can berelatively reduced. Accordingly, an operation for removing the catalystresidue contained in the propylene block copolymer can be omitted, andmoreover in the case of molding the obtained propylene block copolymer,a mold can be easily prevented from occurrence of rust.

In the propylene block copolymer obtained by the above process, acontent of the propylene units is in the range of 50 to 98% by mol,preferably 60 to 97% by mol.

The amount of the decane-soluble component in the propylene blockcopolymer is not more than 50%, and this decane-soluble component mainlycontains a copolymer obtained in the second polymerization stage. Thecomposition of the copolymer varies depending on the kind of olefinused, and hence it cannot be determined generally. However, in thecopolymerization of ethylene with propylene, it is desired that acontent of the propylene units in the copolymer is in the range of 20 to80% by mol, preferably 25 to 75% by mol, particularly preferably 30 to70% by mol. The decane-soluble component desirably has an intrinsicviscosity [η], as measured in decalin at 135° C., of 0.5 to 20 dl/g,preferably 1 to 15 dl/g, more preferably 2 to 12 dl/g, particularlypreferably 2.5 to 10 dl/g.

Further, the MFR of the prepylene bloack copolymer is in the range of0.1 to 500 g/10 min, preferably 0.2 to 300 g/10 min, and is easilycontrolled by varying the conditions of first or second polymerizationstage, such as an amount of feeding hydrogen and polymerizationtemperature.

The propylene polymer and the propylene block copolymer according to theinvention may contain such a nucleating agent as described later. Byadding the nucleating agent to the propylene polymer or the propyleneblock copolymer, the crystal particles can be made more fine and thecrystallization speed can be heightened, whereby high-speed molding isattained.

There is no specific limitation on the nucleating agent employableherein, and various nucleating agents conventionally known can be used.Of various nucleating agents, preferred are those represented by thefollowing formulas.

wherein R¹ is oxygen, sulfur or a hydrocarbon group of 1 to 10 carbonatoms; each of R² and R³ is hydrogen or a hydrocarbon group of 1 to 10carbon atoms; R² and R³ may be the same as or different from each other;two of R², two of R³, or R² and R³ may be bonded together to form aring, M is a monovalent to trivalent metal atom; and n is an integer of1 to 3.

Concrete examples of the nucleating agents represented by the aboveformula includesodium-2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate,sodium-2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate,lithium-2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate,lithium-2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate,sodium-2,2′-ethylidene-bis(4-i-propyl-6-t-butylphenyl)phosphate,lithium-2,2′-methylene-bis(4-methyl-6-t-butylphenyl)phosphate,lithium-2,2′-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate,calcium-bis[2,2′-thiobis(4-methyl-6-t-butylphenyl)phosphate],calcium-bis[2,2′-thiobis(4-ethyl-6-t-butylphenyl)phosphate],calcium-bis[2,2′-thiobis-(4,6-di-t-butylphenyl)phosphate],magnesium-bis[2,2′-thiobis-(4,6-di-t-butylphenyl)phosphate],magnesium-bis[2,2′-thiobis-(4-t-octylphenyl)phosphate],sodium-2,2′-butylidene-bis(4,6-dimethylphenyl)phosphate,sodium-2,2′-butylidene-bis(4,6-di-t-butylphenyl)phosphate,sodium-2,2′-t-octylmethylene-bis(4,6-dimethylphenyl)phosphate,sodium-2,2′-t-octylmethylene-bis(4,6-di-t-butylphenyl)phosphate,calcium-bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate],magnesium-bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate],barium-bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate],sodium-2,2′-methylene-bis(4-methyl-6-t-butylphenyl)phosphate,sodium-2,2′-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate,sodium(4,4′-dimethyl-5,6′-di-t-butyl-2,2′-biphenyl phosphate,calcium-bis[(4,4′-dimethyl-6,6′-di-t-butyl-2,2′-biphenyl)phosphate],sodium-2,2′-ethylidene-bis(4-m-butyl-6-t-butylphenyl)phosphate,sodium-2,2′-methylene-bis(4,6-dimethylphenyl)phosphate,sodium-2,2′-methylene-bis(4,6-diethylphenyl)phosphate,potassium-2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate,calcium-bis[2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate],magnesium-bis[2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate],barium-bis[2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate],aluminum-tris[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate] andaluminum-tris[2,2′-ethylidene-bis(4,6-di-t-butylphenyl)phosphate].Mixtures of two or more of these nucleating agents are also employable.Of these, sodium-2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate isparticularly preferred.

wherein R⁴ is hydrogen or a hydrocarbon group of 1 to 10 carbon atoms; Mis a monovalent to trivalent metal atom; and n is an integer of 1 to 3.

Concrete examples of the nucleating agents represented by the aboveformula include sodium-bis(4-t-butylphenyl) phosphate,sodium-bis(4-methylphenyl)phosphate, sodium-bis(4-ethylphenyl)phosphate,sodium-bis(4-i-propylphenyl) phosphate,sodium-bis(4-t-octylphenyl)phosphate,potassium-bis(4-t-butylphenyl)phosphate, calcium-bis(4-t-butylpheyl)phosphate, magnesium-bis(4-t-butylpheyl)phosphate,lithium-bis(4-t-butylpheyl)phosphate andaluminum-bis(4-t-butylpheyl)phosphate. Mixtures of two or more of thesenucleating agents are also employable. Of these,sodium-bis(4-t-butylphenyl)phosphate is particularly preferred.

wherein R⁵ is hydrogen or a hydrocarbon group of 1 to 10 carbon atoms.

Concrete examples of the nucleating agents represented by the aboveformula include 1,3,2,4-dibenzylidenesorbitol,1,3-benzylidene-2,4-p-ethylbenzylidenesorbitol,1,3-benzylidene-2,4-p-ethylbenzylidenesorbitol,1,3-p-methylbenzylidene-2,4-benzylidenesorbitol,1,3-p-ethylbenzylidene-2,4-benzylidenesorbitol,1,3-p-methylbenzylidene-2,4-p-ethylbenzylidenesorbitol,1,3-p-ethylbenzylidene-2,4-p-methylbenzylidenesorbitol,1,3,2,4-di(p-methylbenzylidene)sorbitol,1,3,2,4-di(p-ethylbenzylidene)sorbitol,1,3,2,4-di(p-n-propylbenzylidene)sorbitol,1,3,2,4-di(p-i-propylbenzylidene)sorbitol,1,3,2,4-di(p-n-butylbenzylidene)sorbitol,1,3,2,4-di(p-s-butylbenzylidene)sorbitol,1,3,2,4-di(p-t-butylbenzylidene)sorbitol,1,3,2,4-di(2′,4′-dimethylbenzylidene)sorbitol,1,3,2,4-di(p-methoxybenzylidene)sorbitol,1,3,2,4-di(p-ethoxybenzylidene)sorbitol,1,3-benzylidene-2,4-p-chlorobenzylidenesorbitol,1,3-p-chlorobenzylidene-2,4-benzylidenesorbitol,1,3-p-chlorobenzylidene-2,4-p-methylbenzylidenesorbitol,1,3-p-chlorobenzylidene-2,4-p-ethylbenzylidenesorbitol,1,3-p-methylbenzylidene-2,4-p-chlorobenzylidenesorbitol,1,3-p-ethylbenzylidene-2,4-p-chlorobenzylidenesorbitol and1,3,2,4-di(p-chlorobenzylidene)sorbitol. Mixtures of two or more ofthese nucleating agents are also employable. Of these,1,3,2,4-dibenzylidenesorbitol, 1,3,2,4-di(p-methylbenzylidene)sorbitol,1,3,2,4-di(p-ethylbenzylidene) sorbitol,1,3-p-chlorobenzylidene-2,4-p-methylbenzylidenesorbitol,1,3,2,4-di(p-chlorobenzylidene) sorbitol and mixtures of two or more ofthese nucleating agents are particularly preferred.

Also employable are other nucleating agents such as metallic salts ofaromatic carboxylic acids and metallic salts of aliphatic carboxylicacids. Concrete examples thereof include aluminum benzoate, aluminump-t-butylbenzoate, sodium adipate, sodium thiophenecarboxylate andsodium pyrrolecarboxylate.

Inorganic compounds such as talc described later may be also used.

In the propylene polymer of the invention, the nucleating agent is usedin an amount of 0.001 to 10 parts by weight, preferably 0.01 to 5 partsby weight, more preferably 0.1 to 3 parts by weight, based on 100 partsby weight of the propylene polymer.

By the use of the nucleating agent in the above-mentioned amount, therecan be obtained a propylene polymer having extremely fine crystallineparticles and enhanced in crystallinity without deterioration ofexcellent properties inherently belonging to the propylene polymer.

In the propylene block copolymer of the invention, the nucleating agentis used in an amount of 0.001 to 10 parts by weight, preferably 0.01 to5 parts by weight, more preferably 0.1 to 3 parts by weight, based on100 parts by weight of the propylene block copolymer.

By the use of the nucleating agent in the above-mentioned amount, therecan be obtained a propylene block copolymer having extremely finecrystalline particles and enhanced in crystallinity withoutdeterioration of excellent properties inherently belonging to thepropylene block copolymer.

To the propylene polymer and the propylene block copolymer of theinvention may be added various additives such as rubber component toenhance impact strength, heat stabilizer, weathering stabilizer,antioxidant, slip agent, antiblocking agent, antifogging agent,lubricant, dye, pigment, natural oil, synthetic oil and wax. They can beadded in appropriate amounts.

Further, to the propylene polymer and the propylene block copolymer ofthe invention may be added fillers such as silica, diatomaceous earth,alumina, titanium oxide, magnesium oxide, pumice powder, pumice balloon,aluminum oxide, magnesium oxide, basic magnesium carbonate, dolomite,calcium sulfate, potassium titanate, barium sulfate, calcium sulfite,talc, clay, mica, asbestos, glass fiber, glass flake, glass bead,calcium silicate, montmorillonite, bentonite, graphite, aluminum powder,molybdenum sulfide, borone fiber, silicon carbide fiber, polyethylenefiber, polypropylene fiber, polyester fiber and polyamide fiber, withthe proviso that the objects of the invention are not marred.

The propylene polymer of the invention can be used without specificlimitation in a field where polypropylene has been conventionally used,and particularly it can be favorably used for extruded sheet,unstretched film, stretched film, filament, injection molded product andblow molded product.

There is no specific limitation on the shape and the kind of theextrusion molded product made of the propylene polymer of the invention.Concretely, there can be mentioned sheet, film (unstretched film), pipe,hose, electric wire cover and filament. The extrusion molded productmade of the propylene polymer is particularly preferably used as sheet,film (unstretched film) and filament.

In order to extrusion mold the propylene polymer of the invention into asheet, a film (unstretched film) or the like, conventionally knownextrusion apparatuses such as a single screw extruder, a kneadingextruder, a ram extruder and a gear extruder can be used. Using suchextruder, a molten propylene polymer is extruded from a T-die or thelike to prepare an extrusion molded product. The extrusion molding canbe carried out under the molding conditions conventionally known.

The extruded sheet and film (unstretched film) prepared as above areexcellent in rigidity, heat resistance and moisture resistance.

A stretched film can be prepared from the above-mentioned sheet or filmmade of the propylene polymer by conventional stretching methods usingknown stretching machines, such as tentering (lengthwise-crosswisestretching, crosswise-lengthwise stretching), simultaneous biaxialstretching (biaxial orientation) and monoaxial stretching. The stretchratio of the biaxially stretched (oriented) film is preferably in therange of 20 to 70 times, while the stretch ratio of the monoaxiallystretched film is preferably in the range of 2 to 10 times. Thethickness of the stretched film is desirably in the range of 5 to 200μm.

Such stretched film is excellent in rigidity, heat resistance andmoisture resistance.

From the propylene polymer of the invention, an inflation film can bealso prepared.

Since the sheet, the unstretched film and the stretched film composed ofthe propylene polymer of the invention are excellent in heat resistance,transparency, see-through properties, glossiness, rigidity, moistureresistance, gas barrier properties, etc., they can be widely applied topackaging films or other uses. In particular, they are very suitable forpress through pack used for packaging of pharmaceutical tablets orcapsules.

The filament composed of the propylene polymer of the invention can beprepared, for example, by extruding a molten propylene polymer through aspinning nozzle. The filament thus obtained may be further subjected tostretching. This stretching is carried out in such a manner that themolecular orientation at least in the monoaxial direction is effectivelygiven to the propylene polymer, and the stretch ratio is desirably inthe range of 5 to 10 times.

Such filament is excellent in rigidity and heat resistance.

The injection molded product composed of the propylene polymer of theinvention can be prepared using a conventionally known injection moldingapparatus. The injection molding can be carried out under the moldingconventionally known. Since the injection molded product is excellent inrigidity, heat resistance, impact resistance, surface glossiness,chemical resistance, abrasion resistance, etc., it can be widely usedfor automotive interior trims, automotive exterior trims, housings forelectrical appliances, containers, etc.

The blow molded product composed of the propylene polymer of theinvention can be prepared using a conventionally known blow moldingapparatus. The blow molding can be carried out under the moldingconditions conventionally known. For example, in the extrusion blowmolding, a molten propylene polymer is extruded from a die to form atubular parison at a resin temperature of 100 to 300° C., then theparison is kept within a mold having an aimed shape, and air is blowninto the mold at a resin temperature of 130 to 300° C. to obtain ahollow molded product. In this case, the stretch ratio is desirablywithin the range of 1.5 to 5 times in the crosswise direction.

In the injection blow molding, a molten propylene polymer is injectedinto a mold to form a parison at a resin temperature of 100 to 300° C.,then the parison is kept within a mold having an aimed shape, and air isblown into the mold at a resin temperature of 120 to 300° C. to obtain ahollow molded product. In this case, the stretch ratio is desirablywithin the range of 1.1 to 1.8 times in the lengthwise direction andwithin the range of 1.3 to 2.5 times in the crosswise direction.

Such blow molded product is excellent in rigidity, heat resistance andmoisture resistance.

The propylene polymer of the invention can be used as a substrate in amethod wherein a skin material and a substrate are subjected to pressmolding at the same time to prepare an integrally molded product (i.e.,mold stamping method). The molded product obtained by the mold stampingcan be favorably used as automotive interior trims such as door trim,rear package trim, sheet back garnish and instrument panel.

The molded product obtained by the mold stamping is excellent inrigidity and heat resistance.

The propylene block copolymer of the invention can be used withoutspecific limitation in a field where polypropylene has beenconventionally used, and particularly it can be favorably used forextruded sheet, filament, injection molded product and blow moldedproduct.

There is no specific limitation on the shape and the kind of theextrusion molded product composed of the propylene block copolymer ofthe invention. Concretely, there can be mentioned sheet, pipe, hose,electric wire cover and filament. The extrusion molded product made ofthe propylene block copolymer is particularly preferably used as sheetand filament.

In order to extrusion mold the propylene block copolymer of theinvention into a sheet, or the like, conventionally known extrusionapparatuses such as a single screw extruder, a kneading extruder, a ramextruder and a gear extruder can be used. Using such extruder, a moltenpropylene block copolymer is extruded from a T-die or the like toprepare an extrusion molded product. The extrusion molding can becarried out under the molding conditions conventionally known.

The extruded sheet prepared as above is excellent in a balance betweenrigidity, heat resistance and impact resistance.

The filament composed of the propylene block copolymer of the inventioncan be prepared, for example, by extruding a molten propylene blockcopolymer through a spinning nozzle. The filament thus obtained may befurther subjected to stretching. This stretching is carried out in sucha manner that the molecular orientation at least in the monoaxialdirection is effectively given to the propylene block copolymer, and thestretch ratio is desirably in the range of 5 to 10 times.

Such filament is excellent in rigidity and heat resistance.

The injection molded product composed of the propylene block copolymerof the invention can be prepared using a conventionally known injectionmolding apparatus. The injection molding can be carried out under themolding conditions conventionally known. Since the injection moldedproduct is excellent in rigidity, heat resistance, impact resistance,surface glossiness, chemical resistance, abrasion resistance, etc., itcan be widely used for automotive interior trims, automotive exteriortrims, housings for electrical appliances, containers, etc.

The blow molded product composed of the propylene block copolymer of theinvention can be prepared using a conventionally known blow moldingapparatus. The blow molding can be carried out under the moldingconditions conventionally known. For example, in the extrusion blowmolding, a molten propylene block copolymer is extruded from a die toform a tubular parison at a resin temperature of 180 to 300° C., thenthe parison is kept within a mold having an aimed shape, and air isblown into the mold at a resin temperature of 130 to 300° C. to obtain ahollow molded product. In this case, the stretch ratio is desirablywithin the range of 1.5 to 5 times in the crosswise direction.

In the injection blow molding, a molten propylene block copolymer isinjected into a mold to form a parison at a resin temperature of 110 to300° C., then the parison is kept within a mold having an aimed shape,and air is blown into the mold at a resin temperature of 120 to 300° C.to obtain a hollow molded product. In this case, the stretch ratio isdesirably within the range of 1.1 to 1.8 times in the lengthwisedirection and within the range of 1.3 to 2.5 times in the crosswisedirection.

Such blow molded product is excellent in rigidity, heat resistance andmoisture resistance.

The propylene block copolymer of the invention can be used as asubstrate in a method wherein a skin material and a substrate aresubjected to press molding at the same time to prepare an integrallymolded product (i.e., mold stamping method). The molded product obtainedby the mold stamping can be favorably used as automotive interior trimssuch as door trim, rear package trim, sheet back garnish and instrumentpanel.

The molded product obtained by the mold stamping is excellent in abalance between rigidity, heat resistance and impact resistance.

Next, the propylene polymer compositions of the invention are described.

The first propylene polymer composition of the invention is formed from:

[A1] the aforesaid propylene polymer, and

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propylenepolymer.

The second propylene polymer composition of the invention is formedfrom:

[A1] the aforesaid propylene polymer,

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propylenepolymer, and

at least one compound selected from the group consisting of [C] anorganophosphite type stabilizer, [D] a thioether type stabilizer, [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight, preferably0.003 to 5 parts by weight, more preferably 0.005 to 3 parts by weight,based on 100 parts by weight of the above propylene polymer.

When the content of the phenol type stabilizer [B] is within the aboverange based on 100 parts by weight of the propylene polymer, heatresistance can be highly improved, the stabilizer is available at a lowcost, and properties of the propylene polymer such as tensile strengthare not deteriorated.

When the content of at least one compound selected from the groupconsisting of the organophosphite type stabilizer [C], the thioethertype stabilizer [D], the hindered amine type stabilizer [E] and themetallic salt of a higher aliphatic acid [F] is within the above rangebased on 100 parts by weight of the propylene polymer, heat resistancecan be highly improved, the stabilizer is available at a low cost, andproperties of the propylene polymer such as tensile strength are notdeteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range, a residual chlorine of the catalyst remained inthe propylene polymer can be sufficiently absorbed, whereby propertiesof the propylene polymer are never deteriorated.

It is particularly preferred that the second propylene polymercomposition of the invention contains the phenol type stabilizer [B] inan amount of 0.005 to 2 parts by weight, the organophosphite typestabilizer [C] in an amount of 0.005 to 2 parts by weight, the thioethertype stabilizer [D] in an amount of 0.005 to 2 parts by weight, thehindered amine type stabilizer [E] in an amount of 0.005 to 2 parts byweight and the metallic salt of higher aliphatic acid [F] in an amountof 0.005 to 2 parts by weight, each based on 100 parts by weight of thepropylene polymer.

The third propylene polymer composition of the invention is formed from:

[A1] the aforesaid propylene polymer, and

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene polymer.

The fourth propylene polymer composition of the invention is formedfrom:

[A1] the aforesaid propylene polymer,

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene polymer, and

at least one compound selected from the group consisting of [D] athioether type stabilizer, [E] a hindered amine type stabilizer and [F]a metallic salt of a higher aliphatic acid in an amount of 0.001 to 10parts by weight, preferably 0.003 to 5 parts by weight, more preferably0.005 to 3 parts by weight, based on 100 parts by weight of the abovepropylene polymer.

When the content of the organophosphite type stabilizer [C] is withinthe above range based on 100 parts by weight of the propylene polymer,heat resistance can be highly improved, the stabilizer is available at alow cost, and properties of the propylene polymer such as tensilestrength are not deteriorated.

When the content of at least one compound selected from the groupconsisting of the thioether type stabilizer [D], the hindered amine typestabilizer [E] and the metallic salt of a higher aliphatic acid [F] iswithin the above range based on 100 parts by weight of the propylenepolymer, heat resistance can be highly improved, the stabilizer isavailable at a low cost, and properties of the propylene polymer such astensile strength are not deteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range, a residual chlorine of the catalyst remained inthe propylene polymer can be sufficiently absorbed, whereby propertiesof the propylene polymer are never deteriorated.

It is particularly preferred that the fourth propylene polymercomposition of the invention contains the organophosphite typestabilizer [C] in an amount of 0.005 to 2 parts by weight, the thioethertype stabilizer [D] in an amount of 0.005 to 2 parts by weight, thehindered amine type stabilizer [E] in an amount of 0.005 to 2 parts byweight and the metallic salt of higher aliphatic acid [F] in an amountof 0.005 to 2 parts by weight, each based on 100 parts by weight of thepropylene polymer [A1].

The fifth propylene polymer composition of the invention is formed from:

[A1] the aforesaid propylene polymer, and

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propylenepolymer.

The sixth propylene polymer composition of the invention is formed from:

[A1] the aforesaid propylene polymer,

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propylenepolymer, and

at least one compound selected from the group consisting of [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight, preferably0.003 to 5 parts by weight, more preferably 0.005 to 3 parts by weight,based on 100 parts by weight of the above propylene polymer.

When the content of the thioether type stabilizer [D] is within theabove range based on 100 parts by weight of the propylene polymer, heatresistance can be highly improved, the stabilizer is available at a lowcost, and properties of the propylene polymer such as tensile strengthare not deteriorated.

When the content of at least one compound selected from the groupconsisting of the hindered amine type stabilizer [E] and the metallicsalt of a higher aliphatic acid [F] is within the above range based on100 parts by weight of the propylene polymer, heat resistance can behighly improved, the stabilizer is available at a low cost, andproperties of the propylene polymer such as tensile strength are notdeteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range, a residual chlorine of the catalyst remained inthe propylene polymer can be sufficiently absorbed, whereby propertiesof the propylene polymer are never deteriorated.

It is particularly preferred that the sixth propylene polymercomposition of the invention contains the thioether type stabilizer [D]in an amount of 0.005 to 2 parts by weight, the hindered amine typestabilizer [E] in an amount of 0.005 to 2 parts by weight and themetallic salt of higher aliphatic acid [F] in an amount of 0.005 to 2parts by weight, each based on 100 parts by weight of the propylenepolymer [A1].

The seventh propylene polymer composition of the invention is formedfrom:

[A1] the aforesaid propylene polymer, and

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene polymer.

The eighth propylene polymer composition of the invention is formedfrom:

[A1] the aforesaid propylene polymer,

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene polymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight, preferably 0.003 to 5 parts by weight, morepreferably 0.005 to 3 parts by weight, based on 100 parts by weight ofthe above propylene polymer.

When the content of the hindered amine type stabilizer [E] is within theabove range based on 100 parts by weight of the propylene polymer, heatresistance can be highly improved, the stabilizer is available at a lowcost, and properties of the propylene polymer such as tensile strengthare not deteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range based on 100 parts by weight of the propylenepolymer, a residual chlorine of the catalyst remained in the propylenepolymer can be sufficiently absorbed, the stabilizer is available at alow cost, and properties of the propylene polymer are neverdeteriorated.

The ninth propylene polymer composition of the invention is formed from:

[A1] the aforesaid propylene polymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight, preferably 0.003 to 5 parts by weight, morepreferably 0.005 to 3 parts by weight, based on 100 parts by weight ofthe above propylene polymer.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range based on 100 parts by weight of the propylenepolymer, a residual chlorine of the catalyst remained in the propylenepolymer can be sufficiently absorbed, the stabilizer is available at alow cost, and properties of the propylene polymer such as tensilestrength are not deteriorated.

The tenth propylene polymer composition of the invention is formed from:

[A2] the aforesaid propylene block copolymer,

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propyleneblock copolymer.

The eleventh propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer,

[B] a phenol type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propyleneblock copolymer, and at least one compound selected from the groupconsisting of [C] an organophosphite type stabilizer, [D] a thioethertype stabilizer, [E] a hindered amine type stabilizer and [F] a metallicsalt of a higher aliphatic acid in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propyleneblock copolymer.

When the content of the phenol type stabilizer [B] is within the aboverange based on 100 parts by weight of the propylene block copolymer,heat resistance can be highly improved, the stabilizer is available at alow cost, and properties of the propylene block copolymer such astensile strength are not deteriorated.

When the content of at least one compound selected from the groupconsisting of the organophosphite type stabilizer [C], the thioethertype stabilizer [D], the hindered amine type stabilizer [E] and themetallic salt of a higher aliphatic acid [F] is within the above rangebased on 100 parts by weight of the propylene block copolymer, heatresistance can be highly improved, the stabilizer is available at a lowcost, and properties of the propylene block copolymer such as tensilestrength are not deteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range, a residual chlorine of the catalyst remained inthe propylene block copolymer can be sufficiently absorbed, wherebyproperties of the propylene block copolymer are never deteriorated.

It is particularly preferred that the eleventh propylene polymercomposition of the invention contains the phenol type stabilizer [B] inan amount of 0.005 to 2 parts by weight, the organophosphite typestabilizer [C] in an amount of 0.005 to 2 parts by weight, the thioethertype stabilizer [D] in an amount of 0.005 to 2 parts by weight, thehindered amine type stabilizer [E] in an amount of 0.005 to 2 parts byweight and the metallic salt of higher aliphatic acid [F] in an amountof 0.005 to 2 parts by weight, each based on 100 parts by weight of thepropylene block copolymer.

The twelfth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer, and

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene block copolymer.

The thirteenth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer,

[C] an organophosphite type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene block copolymer, and

at least one compound selected from the group consisting of [D] athioether type stabilizer, [E] a hindered amine type stabilizer and [F]a metallic salt of a higher aliphatic acid in an amount of 0.001 to 10parts by weight, preferably 0.003 to 5 parts by weight, more preferably0.005 to 3 parts by weight, based on 100 parts by weight of the abovepropylene block copolymer.

When the content of the organophosphite type stabilizer [C] is withinthe above range based on 100 parts by weight of the propylene blockcopolymer, heat resistance can be highly improved, the stabilizer isavailable at a low cost, and properties of the propylene block copolymersuch as tensile strength are not deteriorated.

When the content of at least one compound selected from the groupconsisting of the thioether type stabilizer [D], the hindered amine typestabilizer [E] and the metallic salt of a higher aliphatic acid [F] iswithin the above range based on 100 parts by weight of the propyleneblock copolymer, heat resistance can be highly improved, the stabilizeris available at a low cost, and properties of the propylene blockcopolymer such as tensile strength are not deteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range, a residual chlorine of the catalyst remained inthe propylene block copolymer can be sufficiently absorbed, wherebyproperties of the propylene block copolymer are never deteriorated.

It is particularly preferred that the thirteenth propylene polymercomposition of the invention contains the organophosphite typestabilizer [C] in an amount of 0.005 to 2 parts by weight, the thioethertype stabilizer [D] in an amount of 0.005 to 2 parts by weight, thehindered amine type stabilizer [E] in an amount of 0.005 to 2 parts byweight and the metallic salt of higher aliphatic acid [F] in an amountof 0.005 to 2 parts by weight, each based on 100 parts by weight of thepropylene block copolymer [A2].

The fourteenth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer, and

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propyleneblock copolymer.

The fifteenth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer,

[D] a thioether type stabilizer in an amount of 0.001 to 10 parts byweight, preferably 0.003 to 5 parts by weight, more preferably 0.005 to3 parts by weight, based on 100 parts by weight of the above propyleneblock copolymer, and

at least one compound selected from the group consisting of [E] ahindered amine type stabilizer and [F] a metallic salt of a higheraliphatic acid in an amount of 0.001 to 10 parts by weight, preferably0.003 to 5 parts by weight, more preferably 0.005 to 3 parts by weight,based on 100 parts by weight of the above propylene block copolymer.

When the content of the thioether type stabilizer [D] is within theabove range based on 100 parts by weight of the propylene blockcopolymer, heat resistance can be highly improved, the stabilizer isavailable at a low cost, and properties of the propylene block copolymersuch as tensile strength are not deteriorated.

When the content of at least one compound selected from the groupconsisting of the hindered amine type stabilizer [E] and the metallicsalt of a higher aliphatic acid [F] is within the above range based on100 parts by weight of the propylene block copolymer, heat resistancecan be highly improved, the stabilizer is available at a low cost, andproperties of the propylene block copolymer such as tensile strength arenot deteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range, a residual chlorine of the catalyst remained inthe propylene block copolymer can be sufficiently absorbed, wherebyproperties of the propylene block copolymer are never deteriorated.

It is particularly preferred that the fifteenth propylene polymercomposition of the invention contains the thioether type stabilizer [D]in an amount of 0.005 to 2 parts by weight, the hindered amine typestabilizer [E] in an amount of 0.005 to 2 parts by weight and themetallic salt of higher aliphatic acid [F] in an amount of 0.005 to 2parts by weight, each based on 100 parts by weight of the propyleneblock copolymer [A2].

The sixteenth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer, and

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene block copolymer.

The seventeenth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer,

[E] a hindered amine type stabilizer in an amount of 0.001 to 10 partsby weight, preferably 0.003 to 5 parts by weight, more preferably 0.005to 3 parts by weight, based on 100 parts by weight of the abovepropylene block copolymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight, preferably 0.003 to 5 parts by weight, morepreferably 0.005 to 3 parts by weight, based on 100 parts by weight ofthe above propylene block copolymer.

When the content of the hindered amine type stabilizer [E] is within theabove range based on 100 parts by weight of the propylene blockcopolymer, heat resistance can be highly improved, the stabilizer isavailable at a low cost, and properties of the propylene block copolymersuch as tensile strength are not deteriorated.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range based on 100 parts by weight of the propyleneblock copolymer, a residual chlorine of the catalyst remained in thepropylene block copolymer can be sufficiently absorbed, the stabilizeris available at a low cost, and properties of the propylene blockcopolymer are never deteriorated.

The eighteenth propylene polymer composition of the invention is formedfrom:

[A2] the aforesaid propylene block copolymer, and

[F] a metallic salt of a higher aliphatic acid in an amount of 0.001 to10 parts by weight, preferably 0.003 to 5 parts by weight, morepreferably 0.005 to 3 parts by weight, based on 100 parts by weight ofthe above propylene block copolymer.

When the content of the metallic salt of a higher aliphatic acid [F] iswithin the above range based on 100 parts by weight of the propyleneblock copolymer, a residual chlorine of the catalyst remained in thepropylene block copolymer can be sufficiently absorbed, the stabilizeris available at a low cost, and properties of the propylene blockcopolymer such as tensile strength are not deteriorated.

Next, the stabilizers used in the present invention are explained belowin the order of [B] Phenol type stabilizer, [C] Organophosphite typestabilizer, [D] Thioether type stabilizer,[E] Hindered amine typestabilizer, and [F] Metallic salt of higher aliphatic acid.

Phenol Type Stabilizers [B]

Though conventionally known phenolic compounds are used as phenol typestabilizers without specific restriction, concrete examples of thephenol type stabilizers include

2,6-di-tert-butyl-4-methylphenol,

2,6-di-tert-butyl-4-ethylphenol,

2,6-dicyclohexyl-4-methylphenol,

2,6-diisopropyl-4-ethylphenol,

2,6-di-tert-amyl-4-methylphenol,

2,6-di-tert-octyl-4-n-propylphenol,

2,6-dicyclohexyl-4-n-octylphenol,

2-isopropyl-4-methyl-6-tert-butylphenol,

2-tert-butyl-2-ethyl-6-tert-octylphenol,

2-isobutyl-4-ethyl-6-tert-hexylphenol,

2-cyclohexyl-4-n-butyl-6-isopropylphenol,

dl-α-tocopherol,

tert-butylhydroquinone,

2,2′-methylenebis(4-methyl-6-tert-butylphenol),

4,4′-butylidenebis(3-methyl-6-tert-butylphenol),

4,4′-thiobis(3-methyl-6-tert-butylphenol),

2,2-thiobis(4-methyl-6-tert-butylphenol),

4,4′-methylenebis(2,6-di-tert-butylphenol),

2,2′-methylenebis[6-(1-methylcyclohexyl)-p-cresol],

2,2′-ethylidenebis(2,4-di-tert-butylphenol),

2,2′-butylidenebis(2-tert-butyl-4-methylphenol),

1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,

triethyleneglycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate],

1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],

2,2′-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],

N,N′-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide),

3,5-di-tert-butyl-4-hydroxybenzyl phosphonate diethyl ester,

1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate,

1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate,

tris(4-tert-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate,

2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butyl-anilino)-1,3,5-triazine,

tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane,

bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester)calcium,

bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester)nickel,

bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyric acid] glycol ester,

N,N′-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine,

2,2′-oxamidobis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl propionate],

2,2′-methylenebis(4-methyl-6-tert-butylphenol) terephthalate,

1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,

3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]-undecane,

2,2-bis[4-(2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy))ethoxyphenyl]propane,and

alkyl esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid.

Of these compounds, preferred are

triethyleneglycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate],

1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],

2,2-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],

N,N′-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide),

3,5-di-tert-butyl-4-hydroxybenzyl phosphonate-diethyl ester,

1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate,

1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxyethyl]isocyanurate,

tris(4-tert-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate,

2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine,

tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane,

bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester)calcium,

bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester)nickel,

bis[3,3-bis(3-tert-4-hydroxyphenyl)butyric acid] glycol ester,

N,N′-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine,

2,2′-oxamidobis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],

2,2′-methylenebis(4-methyl-6-tert-butylphenol) terephthalate,

1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,

3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]-undecane,

2,2-bis[4-(2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy))ethoxyphenyl]propane,and

alkyl esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid.

Of the alkyl esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionicacid mentioned above, particularly preferred are alkyl esters havingalkyl group of not greater than 18 carbon atoms.

Furthermore, the following compounds are particularly preferably used inthe present invention:

tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane,

bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester)calcium,

bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester)nickel,

bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyric acid] glycol ester,

N,N′-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine,

2,2′-oxamidobis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],

2,2′-methylenebis(4-methyl-6-tert-butylphenol) terephthalate,

1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,

3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]-undecane,

1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate,and

2,2-bis[4-(2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy))ethoxyphenyl]propane.

These phenol type stabilizers are used singly or in combination.

Organophosphite Type Stabilizers [C]

Though conventionally known organophosphite type stabilizers are usedwithout specific restriction in the present invention, concrete examplesof the organophosphite type stabilizers include

trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyldiphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, triphenylphosphite, tris(butoxyethyl) phosphite, tris(nonylphenyl) phosphite,distearylpentaerithrytol diphosphite,tetra(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butanediphosphite, tetra(C₁₂-C₁₅ mixed alkyl)-4,4′-isopropylidenediphenyldiphosphite,tetra(tridecyl)-4,4′-butylidenebis(3-methyl-6-tert-butylphenol)diphosphite, tris(3,5-di-tert-butyl-4-hydroxyphenyl) phosphite,tris(mixed monononylphenyl, dinonylphenyl) phosphite,hydrogenated-4,4′-isopropylidenediphenol polyphosphite,bis(octylphenyl)-bis[4,4′-butylidenebis(3-methyl-6-tert-butylphenol)]-1,6-hexanedioldiphosphite, phenyl-4,4′-isopropylidenediphenol-pentaerythritoldiphosphite, tris[4,4′-isopropylidenebis(2-tert-butylphenol)] phosphite,phenyl-diisodecyl phosphite, di(nonylphenyl) pentaerythritoldiphosphite, tris(1,3-distearoyloxyisopropyl) phosphite,4,4′-isopropylidenebis(2-tert-butylphenol)-di(nonylphenyl) phosphate,and 9,10-dihydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide.

In addition, bis(dialkylphenyl) pentaerythritiol diphosphite estershaving the formula (iv) of spiro type or the formula (v) of cage typeillustrated below are also used:

Usually, a mixture of both isomers is most often used due to utilizationof an economically advantageous process for manufacturing such phosphiteester.

wherein R¹, R² and R³ are each a hydrogen or an alkyl group having 1 to9 carbon atoms, preferably a branched alkyl group, particularlypreferably a tert-butyl group, the most preferable substitutionpositions of R¹, R² and R³ on the phenyl groups being 2-, 4- and6-positions. Preferable phosphite esters includebis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite and bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, andthere may also be mentioned phosphonites having a structure wherein acarbon atom is directly bonded to a phosphorus atom, such astetrakis(2,4-di-tert-butylphenyl)-4,4′-biphenylene diphosphonite.

These organophosphite type stabilizers are used singly or incombination.

Thioether Type Stabilizers [D]

Though conventionally known thioether type stabilizers are used withoutspecific restriction in the present invention, concrete examples of thethioether type stabilizers include

dialkyl esters such as dilauryl, dimyristyl and distearyl ester ofthiodipropionic acid, esters of alkylthiopropionic acid such as butyl-,octyl-, lauryl- and stearylthiopropionic acid with a polyhydric alcohol(for example, glycerine, trimethylolethane, trimethylolpropane,pentaerythritol and trishydroxyethyliscyanurate), such aspentaerythritoltetralaurylthiopropionate. More concretely, the thioetherstabilizers include dilauryl thiodipropionate, dimyristylthiodipropionate, lauryl stearyl thiodipropionate and distearylthiodibutyrate.

These thioether type stabilizers are used singly or in combination.

Hindered Amine Type Stabilizers [E]

There are used without specific restriction as the hindered amine typestabilizers conventionally known compounds having a structure whereinmethyl groups are substituted for all the hydrogen atoms bonded to thecarbon atoms at the 2- and 6-positions of piperidine. Concrete examplesof the hindered amine type stabilizers include

(1) bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate,

(2) dimethylsuccinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidinepolycondensate,

(3)poly[[6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]],

(4) tetrakis(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate,

(5) 2,2,6,6-tetramethyl-4-piperidyl benzoate

(6)bis(1,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate,

(7) bis-(N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate,

(8) 1,1′-(1,2-ethanediyl)bis(3,3,5,5-tetramethylpiperazinone),

(9) (mixed 2,2,6,6-tetramethyl-4-piperidyl/tridecyl)1,2,3,4-butanetetracarboxylate,

(10) (mixed 1,2,2,6,6-pentamethyl-4-piperidyl/tridecyl)1,2,3,4-butanetetracarboxylate,

(11) mixed{2,2,6,6-tetramethyl-4-piperidyl/β,β,β′,β′-tetramethyl-3,9-[2,4,8,10-tetraoxasprio(5,5)undecane]diethyl}1,2,3,4-butanetetracarboxylate,

(12) mixed{1,2,2,6,6-pentamethyl-4-piperidyl/β,β,β′,β′-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethyl}1,2,3,4-butanetetracarboxylate,

(13)N,N′-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazinecondensate,

(14)poly[[6-N-morpholinyl-1,3,5-triazine-2,4-diyl]-[(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]],

(15) condensate ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine with1,2-dibromoethane, and

(16)[N-(2,2,6,6-tetramethyl-4-piperidyl)-2-methyl-2-(2,2,6,6-tetramethyl-4-piperidyl)imino]propionamide.

Of the hindered amine type stabilizers, those especially preferablyemployed are the compounds denoted by (1), (2), (3), (4), (8), (10),(11), (14) and (15).

These hindered amine type stabilizers are used singly or in combination.

Metallic Salts of Higher Aliphatic Acid [F]

Examples of metallic salts of the higher aliphatic acid which may beused in the invention include alkaline earth metal salts such asmagnesium salts, calcium salts and barium salts, alkali metal salts suchas sodium salts, potassium salts and lithium salts, cadmium salts, zincsalts and lead salts of higher aliphatic acids such as stearic acid,oleic acid, lauric acid, capric acid, ariachidic acid, palmitic acid,behenic acid, 12-hydroxystearic acid, ricinolic acid, and montanic acid.Concrete examples of the metallic salt of higher aliphatic acid include

magnesium stearate, magnesium laurate, magnesium palmitate, calciumstearate, calcium oleate, calcium laurate, barium stearate, bariumoleate, barium laurate, barium arachidate, barium behenate, zincstearate, zinc oleate, zinc laurate, lithium stearate, sodium stearate,sodium palmitate, sodium laurate, potassium stearate, potassium laurate,calcium 12-hydroxystearate and calcium montanate.

These metallic salts of higher aliphatic acid are used singly or incombination.

Metallic salts of higer aliphatic acid as described above act as alubricant and a rust-preventive agent. Propylene polymer compositionscontaining such metallic salts of higher aliphatic acid therefore areexcellent in moldability and effective in rust prevention of moldingmachines, etc.

The propylene polymer compositions of the invention can be used withoutspecific limitation in a field where polypropylene has beenconventionally used, and particularly they can be favorably used forextruded sheet, unstretched film, stretched film, filament, infectionmolded product and blow molded product.

There is no specific limitation on the shape and the kind of theextrusion molded product made of the propylene polymer composition ofthe invention. Concretely, there can be mentioned sheet, film(unstretched film), pipe, hose, electric wire cover and filament. Theextrusion molded product of the propylene polymer composition isparticularly preferably used as sheet, film (unstretched film) andfilament.

In order to extrusion mold the propylene polymer composition of theinvention into a sheet, a film (unstretched film) or the like,conventionally known extrusion apparatuses such as a single screwextruder, a kneading extruder, a ram extruder and a gear extruder can beused. Using such extruder, a molten propylene polymer composition isextruded from a T-die or the like to prepare an extrusion moldedproduct. The extrusion molding can be carried out under the moldingconditions conventionally known.

The extruded sheet and film (unstretched film) prepared as above areexcellent in rigidity, heat resistance and moisture resistance.

A stretched film can be prepared from the above-mentioned sheet or filmmade of the propylene polymer composition by conventional stretchingmethods using known stretching machines, such as tentering(lengthwise-crosswise stretching, crosswise-lengthwise stretching),simultaneous biaxial stretching (biaxial orientation) and monoaxialstretching. The stretch ratio of the biaxially stretched (oriented) filmis preferably in the range of 20 to 70 times, while the stretch ratio ofthe monoaxially stretched film is preferably in the range of 2 to 10times. The thickness of the stretched film is desirably in the range of5 to 200 μm.

Such stretched film is excellent in rigidity, heat resistance andmoisture resistance.

From the propylene polymer composition of the invention, an inflationfilm can be also prepared.

Since the sheet, the unstretched film and the stretched film composed ofthe propylene polymer composition of the invention are excellent in heatresistance, transparency, see-through properties, glossiness, rigidity,moisture resistance, gas barrier properties, etc., they can be widelyapplied to packaging films or other uses. In particular, they are verysuitable for press through pack used for packaging of pharmaceuticaltablets or capsules.

The filament composed of the propylene polymer composition of theinvention can be prepared, for example, by extruding a molten propylenepolymer composition through a spinning nozzle. The filament thusobtained may be further subjected to stretching. This stretching iscarried out in such a manner that the molecular orientation at least inthe monoaxial direction is effectively given to the propylene polymer,and the stretch ratio is desirably in the range of 5 to 10 times.

Such filament is excellent in rigidity and heat resistance.

The injection molded product composed of the propylene polymercomposition of the invention can be prepared using a conventionallyknown injection molding apparatus. The injection molding can be carriedout under the molding conditions conventionally known.

Since the injection molded product is excellent in rigidity, heatresistance, impact resistance, surface glossiness, chemical resistance,abrasion resistance, etc., it can be widely used for automotive interiortrims, automotive exterior trims, housings for electrical appliances,containers, etc.

The blow molded product composed of the propylene polymer composition ofthe invention can be prepared using a conventionally known blow moldingapparatus. The blow molding can be carried out under the moldingconditions conventionally known. For example, in the extrusion blowmolding, a molten propylene polymer composition is extruded from a dieto form a tubular parison at a resin temperature of 100 to 300° C., thenthe parison is kept within a mold having an aimed shape, and air isblown into the mold at a resin temperature of 130 to 300° C. to obtain ahollow molded product. In this case, the stretch ratio is desirablywithin the range of 1.5 to 5 times in the crosswise direction.

In the injection blow molding, a molten propylene polymer composition isinjected into a mold to form a parison at a resin temperature of 100 to300° C., then the parison is kept within the mold having an aimed shape,and air is blown into the mold at a resin temperature of 120 to 300° C.to obtain a hollow molded product. In this case, the stretch ratio isdesirably within the range of 1.1 to 1.8 times in the lengthwisedirection and within the range of 1.3 to 2.5 times in the crosswisedirection.

Such blow molded product is excellent in rigidity, heat resistance andmoisture resistance.

The propylene polymer compositions of the invention can be used as asubstrate in a method wherein a skin material and a substrate aresubjected to press molding at the same time to prepare an integrallymolded product (i.e., mold stamping method). The molded product obtainedby the mold stamping can be favorably used as automotive interior trimssuch as door trim, rear package trim, sheet back garnish and instrumentpanel.

The molded product obtained by the mold stamping is excellent inrigidity and heat resistance.

EFFECT OF THE INVENTION

The propylene polymer of the invention has a high crystallinity of aboiled heptane-insoluble component contained therein and a highstereoregularity, and moreover it has an extremely long mesochain.Hence, the propylene polymer is excellent in rigidity, heat resistanceand moisture resistance.

The propylene block copolymer of the invention has a high crystallinityof a boiled heptane-insoluble component contained therein and a highstereoregularity, and moreover it has an extremely long mesochain.Hence, the propylene block copolymer is well-balanced between rigidity,heat resistance and impact resistance.

The propylene polymer composition of the invention is formed from thepropylene polymer or the propylene block copolymer which has a highcrystallinity of a boiled heptane-insoluble component contained therein,a high stereoregularity and an extremely long mesochain, and a specificstabilizer. Hence, the propylene polymer composition is excellent inheat stability during the molding stage, long-term heat stability,weathering resistance, etc., and moreover a molded product obtained fromthis propylene polymer composition is excellent in rigidity, heatresistance and moisture resistance.

The present invention is further illustrated by the following examples,but the invention is in no way restricted to those examples.

EXAMPLE Example 1

Preparation of Solid Titanium Catalyst Component (A)]

95.2 g of anhydrous magnesium chloride, 442 ml of decane and 390.6 g of2-ethylhexylalcohol were mixed and heated at 130° C. for 2 hours to givea homogeneous solution. Then, to the solution was added 21.3 g ofphthalic anhydride and they were mixed and stirred at 130° C. for 1 hourto dissolve the phthalic anhydride in the solution. The thus obtainedhomogeneous solution was cooled to room temperature, and then 75 ml ofthe homogeneous solution was dropwise added to 200 ml of titaniumtetrachloride kept at −20° C. over a period of 1 hour. After theaddition was completed, the temperature of the resulting mixture liquidwas raised to 110° C. over a period of 4 hours. When the temperature ofthe mixture liquid reached to 110° C., 5.22 g of diisobutyl phthalate(DIBP) was added to the mixture liquid, and then resulting mixture wasstirred at the same temperature for 2 hours.

After the reaction was completed, a solid portion was recovered from thereaction liquid by means of hot filtration. The solid portion wassuspended again in 275 ml of titanium tetrachloride, and the obtainedsuspension was further heated at 110° C. for 2 hours. After the reactionwas completed, a solid portion was recovered again by means of hotfiltration. The solid portion was well washed with decane and hexanekept at 110° C. until no titanium compound liberating in the solutionwas detected.

The solid titanium catalyst component (A) prepared as above was storedas a decane slurry. A part of the slurry was dried to examine thecatalyst composition. The catalyst component (A) obtained had acomposition comprising 2.4% by weight of titanium, 60% by weight ofchlorine, 20% by weight of magnesium and 13.0% by weight of DIBP.

Preparation of Prepolymerized Catalyst (B)

Into a 2-liter autoclave equipped with a stirrer, 500 ml of purifiedhexane, 57.5 g of 3-methyl-1-butene, 50 mmol of triethylaluminum, 50mmol of triemethylmethoxysilane and 5.0 mmol Ti (in terms of titaniumatom) of the above-obtained solid titanium catalyst component (A) werecharged in a nitrogen atmosphere to perform a reaction for 2 hours. Thepolymerization temperature in the autoclave was kept at 20° C.

After the reaction was completed, the reactor was purged with nitrogen,and a washing operation consisting of removal of the supernatant liquidand addition of purified hexane was carried out three times. Thereafter,the obtained reaction liquid was suspended again using purified hexane,and all of the resulting suspension was transferred into a catalystbottle to obtain a prepolymerized catalyst (B). 5.7 g ofpoly-3-methyl-1-butene was produced based on 1 g of the solid titaniumcatalyst component (A).

[Polymerization]

Into a 2-liter autoclave, 750 ml of purified n-hexane was charged, andfurther 0.75 mmol of triethylaluminum, 0.75 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.015 mmol Ti (in terms oftitanium atom) of the above-obtained prepolymerized catalyst (B) werecharged at 60° C. in a propylene atmosphere.

Further, 1200 ml of hydrogen was introduced into the autoclave, and thetemperature in the autoclave was raised to 70° C., followed by keepingthe same temperature for 2 hours to perform a propylene polymerization.The pressure during the polymerization was kept at 7 kg/cm²-G. After thepolymerization was completed, a slurry containing the produced solid wasfiltered and separated into a white powder and a liquid phase portion.

The yield of the white powder polymer was 303.2 g on the dry basis, andthe white powder polymer had a melt flow rate (MFR) of 12.5 g/10 mm andan apparent bulk specific gravity of 0.45 g/ml. Further, the obtainedwhite powder was dissolved in decane for a time, and then graduallycooled to obtain a powder. The amount of the boiled heptane-insolublecomponent contained in this powder was 96.9% by weight and thecrystallinity of the boiled heptane-insoluble component was 75.0%.

On the other hand, 2.0 g of a solvent-soluble polymer was obtained byconcentration of the above-obtained liquid phase portion. Accordingly,the activity was 20,300 g-PP/mM-Ti, and the amount of the boiledheptane-insoluble component contained in the whole polymer was 96.3% byweight.

The results are set forth in Table 1.

Example 2

The procedure of the polymerization as in Example 1 was repeated exceptthat the polymerization temperature was changed to 80° C.

The results are set forth in Table 1.

Example 3

The procedure of the polymerization as in Example 1 was repeated exceptthat the polymerization temperature was changed to 90° C.

The results are set forth in Table 1.

Example 4

[Polymerization]

Into a 2-liter autoclave, 500 g of propylene and 6 liters of hydrogenwere charged, and the temperature in the autoclave was raised to 60° C.Then, 0.6 mmol of triethylaluminum, 0.6 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.006 mmol Ti (in terms oftitanium atom) of the above-obtained prepolymerized catalyst (B) werecharged into the autoclave.

The temperature in the autoclave was raised to 70° C., followed bykeeping the same temperature for 40 minutes to perform a propylenepolymerization. The reaction was terminated by the addition of a smallamount of ethanol. After the unreacted propylene was removed, a whitepowder polymer was dried under a reduced pressure.

The results are set forth in Table 1.

Example 5

The procedure of the polymerization as in Example 1 was repeated exceptthat the polymerization temperature was changed to 80° C.

The results are set forth in Table 1.

Comparative Example 1

The procedure of the polymerization as in Example 1 was repeated exceptthat 0.075 mmol of cyclopentyldimethyoxysilane was used instead of theDCPMS and 500 ml of hydrogen was used.

The results are set forth in Table 1.

Comparative Example 2

The procedure of the polymerization as in Example 1 was repeated exceptthat 0.075 mmol of diphenyldimethoxysilane was used instead of the DCPMSand 700 ml of hydrogen was used.

The results are set forth in Table 1.

Comparative Example 3

[Preparation of Solid Titanium Catalyst Component (C)]

1.2 mol of diisoamylether was dropwise added to a mixture of 500 ml ofn-hexane and 0.5 mol of diethylaluminum chloride at 25° C. over a periodof 2 minutes to perform a reaction for 10 minutes.

A 2-liter reactor thoroughly purged with nitrogen was charged with 4.0mol of titanium tetrachloride, and the temperature in the reactor wasraised to 35° C. To the reactor, the above reaction solution wasdropwise added over a period 3 hours, followed by keeping the sametemperature for 30 minutes. Then, the temperature in the reactor wasraised to 75° C. and the reaction was further performed for 1 hour. Theresulting reaction solution was cooled to room temperature and thesupernatant liquid was removed, and then the thus produced solid waswashed with 1 liter of hexane. The washing operation was further carriedout three times.

100 g of the obtained solid was suspended using 2 liter of n-hexane, andto the resulting suspension were added 80 g of diisoamylether and 180 gof titanium tetrachloride at room temperature over a period of 1 minuteto perform a reaction at 65° C. for 1 hour. After the reaction wascompleted, the temperature was cooled to room temperature and thesupernatant was removed by decantation. The thus produced solid waswashed with 2 liters of hexane. Then, the washing operation was furthercarried out three times, to thereby obtain a solid titanium catalystcomponent (C).

[Preparation of Prepolymerized Catalyst (D)]

Into a 2-liter autoclave equipped with a stirrer, 1 liter of purifiedhexane, 30 mmol of diethylaluminum chloride and 3 g of theabove-obtained solid titanium catalyst component (C) were charged in anitrogen atmosphere. Thereafter, 2 liters of hydrogen was introducedinto the autoclave and propylene was fed to the reactor to perform aprepolymerization for 5 minutes. The pressure during the reaction waskept at 5 kg/cm²-G.

After the reaction was completed, the unreacted propylene and hydrogenwere removed and the reactor was purged with nitrogen, and a washingoperation consisting of removal of supernatant liquid and addition ofpurified hexane was carried out three times, to thereby obtain aprepolymerized catalyst (D). The thus obtained prepolymerized catalyst(D) was suspended again using purified decane and stored.

[Polymerization]

Into a 2-liter autoclave equipped with a stirrer, 750 ml of purifiedn-hexane was charged, and further 0.75 mmol of diethylaluminum chloride,0.75 mmol of p-toluic acid methyl ester and 1.1 g of the above-obtainedprepolymerized catalyst (D) were charged at 60° C. in a propyleneatmosphere.

Further, 8 liters of hydrogen was introduced into the autoclave, and thetemperature in the autoclave was raised to 70° C., followed by keepingthe same temperature for 4 hours to perform a propylene polymerization.The pressure during the polymerization was kept at 7 kg/cm²-G. After thepolymerization was completed, 200 ml of methanol was added to theresulting mixture and the temperature was raised to 80° C. After 30minutes, 1 ml of an aqueous solution containing 20% of sodium hydroxidewas added to the resulting mixture and the unreacted gas was removed.

After the liquid phase was removed, the resulting hexane slurry waswashed with 300 ml of deionized water for 20 minutes and the aqueousphase was removed. Then, the hexane slurry was filtered, and then washedand dried, to thereby obtain a polypropylene powder.

The results are set forth in Table 1.

TABLE 1 Amount of Appar- boiled ent heptene- Boiled heptane- bulkinsoluble insoluble component MFR specific compo- Crystal- Activity g/10gravity nent linity *1) min (g/ml) (wt %) (%) [M₅] [M₃] Ex 1 20,300 12.50.45 96.3 75.0 0.992 0.0027 Ex. 2 25,300 21.2 0.42 96.5 78.5 0.9940.0025 Ex. 3 25,500 33.4 0.40 96.9 79.3 0.995 0.0025 Ex. 4 17,200 16.00.47 96.2 74.8 0.992 0.0029 Ex. 5 22,700 23.5 0.40 96.6 78.9 0.9940.0026 Comp 19,300 11.0 0.45 90.0 65.3 0.965 0.0036 Ex. 1 Comp 20,00013.8 0.45 90.9 65.0 0.966 0.0036 Ex. 2 Comp  1,000 16.0 0.35 92.5 58.50.980 0.0017 Ex. 3 *1) g-pp/mmol-Ti

Example 6

[Polymerization]

Into a 2-liter autoclave, 500 g of propylene and 17 liters of hydrogenwas charged, and the temperature in the autoclave was raised to 60° C.Then, 0.6 mmol of triethylaluminum, 0.6 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.006 mmol Ti (in terms oftitanium atom) of the above-obtained prepolymerized catalyst (B) werecharged into the autoclave. The temperature in the autoclave was raisedto 70° C., followed by keeping the same temperature for 40 minutes toperform a propylene homopolymerization. After the hompolymerization wascompleted, a vent valve was opened and the unreacted propylene wasremoved until the pressure in the autoclave reached to atmosphericpressure.

After the removal was completed, ethylene and propylene werecopolymerized under conditions such that ethylene, propylene andhydrogen were fed into the autoclave at 80N-liter/hr, 120N-liter/hr and2N-liter/hr, respectively. The vent opening degree of the autoclave wascontrolled so that the pressure in the autoclave was kept at 10 kg/cm².The temperature in the autoclave was kept at 70° C. to perform apolymerization for 60 minutes. The polymerization reaction wasterminated by the addition of a small amount of ethanol and theunreacted gas in the autoclave was purged out.

The yield of the white powder polymer was 143.3 g, and the polymer had amelt flow rate (MFR) of 48 g/10 min and an apparent bulk specificgravity of 0.44 g/ml. The amount of a decane-soluble component in thewhite powder polymer was 11.4% by weight and the intrinsic viscosity [η]of the decane-soluble component was 3.7 dl/g.

Further, the amount of the boiled heptane-insoluble component in thedecane-insoluble component was 94.4% by weight, the [M₅] value, [M₃]value and crystallinity of the boiled heptane-insoluble component were0.991, 0.0035 and 73.2%, respectively.

Example 7 [Polymerization]

The procedure as in Example 6 was repeated except that hydrogen was notused during the copolymerization.

The results are set forth in Table 2.

Example 8 [Polymerization]

The procedure as in Example 6 was repeated except that the temperatureof the propylene homopolymerization was changed to 80° C.

The results are set forth in Table 2.

Example 9

[Polymerization]

Into a 2-liter autoclave, 750 ml of purified n-hexane was charged, andfurther 0.75 mmol of triethylaluminum, 0.75 mmol ofdicyclopentadimethoxysilane (DCPMS) and 0.015 mmol Ti (in terms oftitanium atom) of the above-obtained prepolymerized catalyst (B) werecharged at 60° C. in a propylene atmosphere.

Then, 2700 ml of hydrogen was introduced into the autoclave and thetemperature in the autoclave was raised to 70° C., followed by keepingthe same temperature for 2 hours to perform a propylenehomopolymerization. The pressure during the polymerization was kept at 7Kg/cm²-G. After the homopolymerization was completed, the unreacted gaswas purged out until the pressure in the autoclave reached toatmospheric pressure.

Thereafter, 120 ml of hydrogen was introduced, and ethylene andpropylene were copolymerized under conditions such that a mixture gas of64 mol % of propylene and 36 mol % of ethylene were fed to perform acopolymerization at 70° C. for 1 hour. The pressure during thepolymerization was kept at 2 Kg/cm²-G. After the reaction was completed,the resulting slurry containing the produced solid was filtered, tothereby obtain a white powder polymer.

The yield of the white powder polymer was 372.2 g on the dry basis, andthe white powder polymer had a melt flow rate (MFR) of 46 g/10 min, andan apparent bulk specific gravity of 0.45 g/ml. The amount of adecane-soluble component in the white powder polymer was 12.0% by weightand the intrinsic viscosity [η] of the decane-soluble component was 3.9dl/g.

Further, the amount of the boiled heptane-insoluble component containedin the decane-insoluble component was 94.7% by weight, the [M₅] value,[M₃] value and crystallinity of the boiled heptane-insoluble componentwere 0.992, 0.0035 and 73.5%, respectively.

Example 10

[Polymerization]

The procedure as in Example 9 was repeated except that hydrogen was notused during the copolymerization.

The results are set forth in Table 2.

Example 11

[Polymerization]

The procedure as in Example 9 was repeated except that the propylenehomopolymerization temperature was changed to 80° C.

The results are set forth in Table 2.

Example 12

[Polymerization]

The procedure as in Example 9 was repeated except that the propylenehomopolymerization temperature was changed to 90° C.

The results are set forth in Table 2.

Example 13

[Polymerization]

The procedure as in Example 7 was repeated except thathexyltrimethoxysilane was used instead of dicyclopentyldimethoxysilane.

The results are set forth in Table 2.

Example 14

[Polymerization]

The procedure as in Example 13 was repeated except that the propylenehomopolymerization temperature was 80° C.

The results are set forth in Table 2.

Comparative Example 4

The procedure as in Example 9 was repeated except that 0.075 mmol ofdiphenyldimethoxysilane was used instead of DCPMS and 1600 ml ofhydrogen was used during the homopolymerization.

The results are set forth in Table 2.

Comparative Example 5

The procedure of the polymerization as in Comparative Example 4 wasrepeated except that hydrogen was not used during the copolymerization.

The results are set forth in Table 2.

Comparative Example 6

[Preparation of Solid Titanium Catalyst Component (E)]

1.2 mol of diisoamylether was dropwise added to a mixture of 500 ml ofn-hexane and 0.5 mol of diethylaluminum chloride at 25° C. over a periodof 2 minutes to perform a reaction for 10 minutes.

A 2-liter rector throughly purged with nitrogen was charged with 4.0 molof titanium tetrachloride, and the temperature in the reactor was raisedto 35° C. To the reactor, the above prepared reaction solution wasdropwise added over a period of 3 hours, followed by keeping the sametemperature for 30 minutes. Then, the temperature in the reactor wasraised to 75° C. and the reaction was further performed for 1 hour. Theresulting reaction solution was cooled to room temperature and thesupernatant liquid was removed. Then, the thus produced solid was washedwith 1 liter of hexane. The washing operation was further carried outthree times.

100 g of the obtained solid was suspended using 2 liter of n-hexane, andto the resulting suspension were added 80 g of isoamylether and 180 g oftitanium tetrachloride at room temperature over a period of 1 minute toperform a reaction at 65° C. for 1 hour. After the reaction wascompleted, the temperature was cooled to room temperature and thesupernatant was removed by decantation. The thus produced solid waswashed with 2 liters of hexane. Then, the washing operation was furthercarried out three times to thereby obtain a solid titanium catalystcomponent (E).

[Preparation of Prepolymerized Catalyst (F)]

Into a 2-liter reactor equipped with a stirrer, 1 liter of purifiedhexane, 30 mmol of diethylaluminum chloride and 3 g of theabove-obtained solid titanium catalyst component (E) were charged in anitrogen atmosphere. Thereafter, 2 liters of hydrogen was introducedinto the reactor and propylene was fed to the reactor to perform aprepolymerization for 5 minutes. The pressure during the reaction waskept at 5 Kg/cm²-G.

After the reaction was completed, the unreacted propylene and hydrogenwere removed and the reactor was purged with nitrogen, and a washingoperation consisting of removal of the supernatant liquid and additionof purified hexane was carried out three times, to thereby obtain aprepolymerized catalyst (F). The thus obtained prepolymerized catalyst(F) was suspended again using purified decane and stored.

[Polymerization]

Into a 2-liter autoclave equipped with stirrer, 750 ml of purifiedn-hexane was charged, and further 0.75 mmol of diethylaluminum chloride,0.75 mmol of p-toluic acid methyl ester and 1.1 g of the above obtainedprepolymerized catalyst (F) were charged at 60° C. in a propyleneatmosphere.

Further, 18 liters of hydrogen was introduced into the autoclave, andthe temperature in the autoclave was raised to 70° C., followed bykeeping the same temperature for 4 hours to perform a propylenepolymerization. The pressure during the polymerization was kept at 7Kg/cm²-G. After the homopolymerization was completed, the unreacted gaswas purged out until the pressure reached to atmospheric pressure.

Thereafter, 120 ml of hydrogen was introduced, and ethylene andpropylene were copolymerized under conditions such that a mixture gas of64 mol % of propylene and 36 mol % of ethylene were fed to perform acopolymerization at 70° C. for 2 hours. The pressure during thepolymerization was kept at 2 Kg/cm²-G. After the reaction was completed,200 ml of methanol was added to the resulting mixture and thetemperature was raised to 80° C. After 30 minutes, 1 ml of an aqueoussolution containing 20% of sodium hydroxide was added to the resultingmixture and the unreacted gas was removed.

After the liquid phase was removed, the resulting hexane slurry waswashed with 300 ml of deionized water for 20 minutes and the aqueousphase was removed. Then, the hexane slurry was filtered, and then washedand dried, to thereby obtain a white solid. The properties of the hexaneslurry were poor and a considerable white turbidity was observed.

The results are set forth in Table 2.

TABLE 2 Amount of boiled heptane- insoluble component in ApparentDecane- decane- Activity bulk soluble insoluble Boiled heptane- g/ MFRspecific component component at insoluble component mmol- g/10 gravity[η] 23° C. Crystal- Ti min g/ml wt % dl/g wt % linity [M₅] [M₃] Ex. 623,900 48 0.44 11.4 3.7 94.4 73.2 0.991 0.0035 Ex. 7 22,800 41 0.45 8.86.7 95.0 73.0 0.991 0.0036 Ex. 8 26,700 52 0.42 9.3 3.9 95.8 74.0 0.9940.0032 Ex. 9 24,800 46 0.45 12.0 3.9 94.7 73.5 0.992 0.0035 Ex. 1024,100 40 0.46 9.5 6.6 94.9 73.3 0.992 0.0031 Ex. 11 26,000 51 0.44 9.73.7 95.4 74.4 0.994 0.0030 Ex. 12 25,500 56 0.42 9.2 3.6 95.8 75.0 0.9950.0029 Ex. 13 21,800 45 0.45 8.0 6.3 94.6 72.1 0.990 0.0035 Ex. 1426,200 55 0.44 7.1 6.2 95.4 73.4 0.993 0.0034 Comp 25,100 52 0.45 13.02.3 90.8 66.7 0.960 0.0036 Ex. 4 Comp 23,700 43 0.46 9.2 4.3 91.1 66.30.962 0.0038 Ex. 5 Comp  1,200 34 0.29 18.0 3.0 84.3 62.6 0.978 0.0016Ex. 6

Examples 15 to 45 and Comparative Example 7

To a propylene polymer having such properties that a melt flow rate is10 g/10 min (MFR:ASTM D1238, 230° C., 2.16 kg load), and a boiledheptane-insoluble component therein satisfies [M₅] of 0.992, [M₃] of0.0027 and a crystallinity of 72.6%, various stabilizers as indicated inTable 3 were added in an amount indicated in Table 3. The resultingmixture was pelletized at 230° C. by means of an extruder having a screwdiameter of 45 mmφ.

The thus obtained pellets were formed by means of a commerciallyavailable T-die film forming machine equipped with an extruder of 65 mmφinto a film of 420 mm in width and 0.04 mm in thickness. At the time offilm forming, the resin temperature was 250° C., the film forming speedwas 20 m/min, and a draft ratio was 0.6.

MFR, heat aging resistance and weathering resistance of the filmobtained were evaluated.

The results are set forth in Table 4.

Estimation of the stabilizers of films are measured by the followingmethods.

Thermal Stability in the Molding Stage

MFR of films: The films shows better thermal stability when thedifference between the MFR of the pellets and that of the film issmaller.

Long-term Heat Stability

A film is aged at 100° C. in a gear oven, and a period of time from thestart of aging to the time when the tensile elongation becomes ½ of thatof the initial value is measured.

The film has better heat-resistant and aging-resistant properties whenit shows a longer period of time.

Weathering Resistance

A film is irradiated with light for 500 hours by using a sunshineweatherometer at a discharge voltage of 50 V and a discharge current of60 A, and with rain, and a retention of tensile elongation thereof ismeasured.

The film has better weathering resistance when it shows a largerretention of tensile elongation.

TABLE 3 Types of Stabilizers and Amounts added (parts by weight/parts byweight-PP) Organic Hindered Phenolic Phosphite Thioether Amine MetalSalts of Higher Stabilizer Stabilizer Stabilizer Stabilizer AliphaticAcid A B C D E F G H I J K L M Ex. 15 0.10 — 0.10 — — — — — — — — — —Ex. 16 — 0.10 — 0.10 — — — — — — — — — Ex. 17 0.10 — — — 0.10 — — — — —— — — Ex. 18 — 0.10 — — 0.10 — — — — — — — — Ex. 19 0.10 — — — — — —0.10 — — — — — Ex. 20 — 0.10 — — — — — 0.10 — — — — — Ex. 21 0.10 — — —— — — — — 0.10 — — — Ex. 22 0.10 — — — — — — — 0.10 — — — Ex. 23 — —0.10 — 0.10 — — — — — — — — Ex. 24 — — — 0.10 0.10 — — — — — — — — Ex.25 — — 0.10 — — — — 0.10 — — — — — Ex. 26 — — — 0.10 — — — 0.10 — — — —— Ex. 27 — — 0.10 — — — — — — 0.10 — — — Ex. 28 — — — 0.10 — — — — —0.10 — — — Ex. 29 — — — — 0.10 — — 0.10 — — — — — Ex. 30 — — — — — 0.10— 0.10 — — — — — Ex. 31 — — — — — — 0.10 0.10 — — — — — Ex. 32 — — — —0.10 — — — — 0.10 — — — Ex. 33 — — — — — 0.10 — — — 0.10 — — — Ex. 34 —— — — — — 0.10 — — 0.10 — — — Ex. 35 — — — — 0.10 — — 0.10 — 0.10 — — —Ex. 36 — — — — — — — 0.10 — 0.10 — — — Ex. 37 — — — — — — — — 0.10 0.10— — — Ex. 38 — — — — — 0.10 0.10 0.10 — — — Ex. 39 — — — — — — — — —0.10 — — — Ex. 40 — — — — — — — — — — 0.10 — — Ex. 41 — — — — — — — — —— — 0.10 — Ex. 42 — — — — — — — — — — — — 0.10 Ex. 43 — — — — — — — — —0.10 0.10 — — Ex. 44 — — — — — — — — — 0.10 — 0.10 — Ex. 45 — — — — — —— — — 0.10 — — 0.10 Comp. — — — — — — — — — — — Ex. 7

The stabilizers used in the Examples are listed as follows.

Used Stabilizers

Phenol Type Stabilizes

A: Stearyl ester of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionicacid. (trade name; Irganox 1076, from Nippon Ciba Geigy, Co.)

B:Tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane(trade name; Irganox 1010, from Nippon Ciba Geigy, Co.)

Organophosphite Type Stabilizers

C: Tris(2,4-di-tert-butylphenyl) phosphite (trade name; Phosphite 168,from Nippon Ciba Geigy, Co.)

D: Tetrakis(2,4-d-tert-butylphenyl)-4,4′-biphenylene diphosphonite(trade name; Sandostab P-EPQ, from Sandoz, Co.)

Thioether Type Stabilizers

E: Dilauryl thiodipropionate (trade name; Antiox L, from Nippon Yusi,Co.)

F: Distearyl thiodipropionate (trade name: DSTP “Yoshitomi”, fromYoshitomi Pharmacy, Co.)

G: Pentaerythritol tetra β-mercapto laurylthiopropionate (trade name:Seenox 412S, from Shipro Chemical, Co.)

Hindered Amine Type Stabilizers

H: Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (trade name: SanolLS770, from Sankyo, Co.)

I:Poly[[6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl][(2,2,6,6,-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]](trade name: Chimassorb 944LD, from Nippon Ciba Geigy, Co.)

Metal Salts of Higher Aliphatic Acid

J: Calcium stearate

K: Calcium 12-hydroxystearate

L: Magnesium Stearate

M: Calcium montanate

TABLE 4 Resistance to heat Weathering MFR aging resistance Pellet Film(day) (%) Ex. 15 10.0 10.5 30 20 Ex. 16 10.0 11.0 28 20 Ex. 17 10.0 11.030 25 Ex. 18 10.0 10.5 26 20 Ex. 19 10.0 11.0 28 25 Ex. 20 10.0 11.0 3030 Ex. 21 10.0 10.5 35 30 Ex. 22 10.0 10.0 35 30 Ex. 23 10.0 11.0 70 25Ex. 24 10.0 10.5 80 30 Ex. 25 10.0 10.5 100  25 Ex. 26 10.0 11.0 120  25Ex. 27 10.0 10.0 120  35 Ex. 28 10.0 10.0 120  30 Ex. 29 10.0 11.5 45 20Ex. 30 10.0 11.5 50 25 Ex. 31 10.0 12.0 50 25 Ex. 32 10.0 11.5 50 25 Ex.33 10.0 12.5 55 30 Ex. 34 10.0 11.0 55 30 Ex. 35 10.0 10.5 70 40 Ex. 3610.0 13.0 150  50 Ex. 37 10.0 12.0 220  55 Ex. 38 10.0 12.0 250  70 Ex.39 10.0 12.0 25 25 Ex. 40 10.0 12.5 25 25 Ex. 41 10.0 13.0 30 25 Ex. 4210.0 13.5 25 25 Ex. 43 10.0 11.5 35 30 Ex. 44 10.0 11.5 40 35 Ex. 4510.0 12.0 35 30 Comp. Ex. 7 15.0 29.0 13 10

What is claimed is:
 1. A process for preparing a propylene blockcopolymer, which comprises a first polymerization stage forhomopolymerizing propylene or copolymerizing propylene with ethyleneand/or α-olefin of 4 to 10 carbon atoms to prepare a crystalline polymerand a second polymerization stage for copolymerizing two or moremonomers selected from α-olefin of 2 to 20 carbon atoms to prepare alow-crystalline or non-crystalline copolymer, in the presence of acatalyst for olefin polymerization comprising: (I) a prepolymerizedcatalyst obtained by prepolymerizing at least one reactive monomerrepresented by the following formula (I) or (ii) using (a) a solidtitanium catalyst component containing magnesium, titanium, halogen andan electron donor as essential components, (b) an organometalliccatalyst component and an organosilicon compound represented by thefollowing formula (c-i); R_(n)Si(OR′)_(4−n)  (c-i) wherein each of R andR is a hydrocarbon group, and n is a number satisfying the condition of0<n<4, said reactive monomer being prepolymerized in an amount of 0.1 to1,000 g per 1 g of the solid titanium catalyst component (a);H₂C═CH—X  (i) H₂C═CH—CH₂—X  (ii) wherein X is a cycloalkyl group, anaryl group or

M is carbon or silicon, R¹ and R² are each a hydrocarbon group, and R³is hydrogen or a hydrocarbon group; (II) the organometallic catalystcomponent (b); and (III) a silicon compound represented by the followingformula (iii) or a compound having at least two ether linkages existingvia plurality of atoms: R^(a) _(n)—Si—(OR^(b))_(4−n)  (iii) wherein, nis 1, 2 or 3; when n is 1, R^(a) is a secondary or a tertiaryhydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or a tertiary hydrocarbon group, Ra may be the same ordifferent, and R^(b) is a hydrocarbon group of 1 to 4 carbon atoms; andwhen 4−n is 2 or 3, R^(b) may be the same or different.